STM under SEM observation with laser excitation of the specimen
A home made piezoscanner, designed for xy scanning of the sample, is hosted on the sample stage of a modified Cambridge S200 scanning electron microscope, while the STM tip is positioned on the desired feature under study by a ρ,θ,φ nanomanipulator. This configuration is the most suitable to minimize mechanical vibration of the STM; alternatively, a particularly low weight scanner is mounted on the nanomanipulator while the sample is fixed. Laser beams can be directed to the interaction zone through an optical port at the back of the SEM chamber, which also serves for microscopic observation of the laser beam alignment on the STM junction. Directing the Laser beam onto the tip allows tip enhanced localised laser nanostructuring (ablation or multiphoton deposition) and localised spectroscopy.
A scheme of the STM-SEM facility is reported below (left). The images on the right show an optical microscope view of the laser irradiated STM tip on the sample, and an SEM scan of the STM tip operating to deposit material on the tips of a couple of lithographic nanoelectrodes fabricated by A. Gerardino at the CNR-IFN electron beam facility. 
This facility is particularly useful for precise positioning of the tip on the specific features or devices to be analyzed or operated upon. It allows STM electronic spectroscopy to be effected on features previously easily located on the basis of the difference in secondary electron emission. It allows a prompt characterization of both tip and sample surface damage. It supplies a first easy characterization of surface modifications, like nanometric pit formation or inorganic material depositions, when the sample is irradiated by laser beams. Finally it gives us the possibility to effect much shorter, and as a consequence slower and less damaging, STM scans for a complete characterization of the sample.
Nanomanipulated Piezoelectric Dynamometers (AFM and Piezoresistive Cantilevers)
Within the general issue of nanofabrication in our laboratory we are interested in controlling the applied forces during sharp probe interaction with the samples. We have purchased commercial piezoresistive cantilever based dynomometer probes and are planning to build more sensitive ones. Attaching this kind of piezoresistive or mechanical probes to a piezoelectric inertial nanomanipulator allows measurement of the stiffness and compliance of a wide range of materials. If the interaction is made under electron microscopy observation, we can easily gain a practical experience on the interaction of sharp tips with materials. We show here how a commercial AFM probe can be stressed and used to dig pits on a gold surface (movie), how we can measure the sensitivity of insects’ tactile hair sensors (movie), how we can measure the compliance of carbon nanotubes wool (movie), and even how we can accomplish a micrometric electrical switch based on a carbon nanotubes helical spring (movie).
UHV STM with microscopic spectral analysis capabilities
This facility based at the ENEA laboratories is hosted in a 35 l ionically pumped ultra-high vacuum vessel endowed with a home made STM, a Z inertial piezo slider for sample approach and a remotely controlled ρ,θ,φ nanomanipulator for sample movement with submicron precision. The vessel has two load-lock chambers for tip and sample load and a hand actuated wobbling pincer for manual operations. It also has optical ports for access to the tip region by two different laser beams.
Above on the left is the scheme of the UHV STM system coupled to the available laser sources and to the spectroscopic analysis system devoted to “tip-enhanced” photoluminescence studies. On the right, a photograph of the UHV vacuum vessel with its lid lifted shows details of the optical microscope case and of the STM. Below, an optical microscope image of the STM tip over a layer of Rhodamine 6G fluorescent dye in white light (left) and excited by a green laser (540 nm) as recorded through a long wavelength pass filter with cutoff at 560 nm with the tip within tunnelling distance (center) and 5 μm away from the surface (right). Light from the tip-enhancement area is spatially selected by a moveable pinhole and analyzed by a monochromator producing the R6G emission spectrum reported below.
Bottom-up Nanofabrication by Lasers and Scanning Probes
The idea that bottom up nanofabrication can be achieved by the joint use of nanometrically controlled sharp tips and electromagnetic radiation. If we think of an irradiated STM tip as an electromagnetic antenna operating at optical rather than radio frequencies, we can understand how, in the vicinity of its highly curved apex,…
Prof. Giovanni Ciccotti
Contact Details
Professor in Structure of Matter
Department of Physics,
University of Rome La Sapienza,
Piazzale Aldo Moro 2, 00185 Rome ITALY
Tel: +39 06 49914378
Fax: +39 06 4957697
Research Outline
Molecular Dynamics and Monte Carlo of Statistical Mechanical Systems
The focus of my research activity is on developing algorithms fro Molecular Dynamics simulation of complex systems in condensed matter phases. From the from now ancient SHAKE algorithm (a procedure to introduce holonomic constraints in MD) or the Subtraction Technique (a noise reducing approach to compute the response to weak external fields in Nonequilibrium MD) to the introduction of the Blue Moon’s ensemble (to simulate in MD rare events) and techniques to simulate Brownian motion to the most recent, and still very active, field of rigorous algorithms to compute nonadiabatic quantum-classical dynamics, the attempt is to widen the domain of computer simulation in condensed matter with a particular emphasis on MD (as distinguished from the very close but different MC- Monte Carlo). Together with that, I have been, and still am, also interested in challenging applications od atomistic MD simulations ranging from surface/interface physics problems in Materials sciences to simulations of biological molecules to find atomistic level explanations of their behavior or functioning mechanisms. More generally, I am interested in considering a variety of developments/applications in the simulation of systems of Statistical Mechanics interest.
Curriculum Vitae et Studiorum
Full List of Publications
Most Recent Publications
[135] E.Vanden Eijnden, and G. Ciccotti, “Second-order integrators for Langevin equations with holonomic constraints”, Chem. Phys. Lett., 429, 310, (2006)
[134] M. S. Causo, G. Ciccotti, S.Bonella, and R. Vuilleumier, “An adiabatic linearized path integral approach for quantum time correlation functions II: A cumulant expansion method for improving convergence”, J. Phys. Chem. B, 110, 3638, (2006)
[135] V. Marry, and G. Ciccotti, “Trotter derived algorithms for molecular dynamics with constraints : Velocity Verlet revisited”, J. Comp. Phys., 222, 428, (2007)
[132] L. Maragliano, A. Fischer, E. Vanden Eijnden, and G. Ciccotti, “String method in collective variables: minimum free energy paths and isocommittor surfaces”, J. Chem. Phys., 125, 024106, (2006).
[131_B] R. Kapral, and G. Ciccotti, “Transport Coefficients of Quantum-Classical Systems”, in “Computer Simulations in Condensed Matter: From Materials to Chemical Biology (The Erice Lectures)”, M. Ferrario, G. Ciccotti, and K. Binder Eds, LNP, Springer Verlag, (2006).
[130_B] G. Ciccotti, D. Coker, and R. Kapral, “Quantum statistical dynamics with trajectories”, in Quantum Dynamics of Complex Molecular Systems, p. 275-294, I. Burghardt and D. Micha Eds, Springer Verlag, Berlin, (2007)
[129] G. Kalibaeva, R. Vuilleumier, S.Meloni, A. Alavi, G. Ciccotti, and R. Rosei, “Ab initio simulation of carbon clustering on Ni(111) surface: a model of the poisoning of nickel based catalysts”, J. Phys. Chem. B, 110, 3638, (2006)
[128] F. Pizzitutti, A. Giansanti, P. Ballario, P. Ornaghi, P. Torreri, G. Ciccotti, and P. Filetici, “Relevant role of loop ZA and Pro371 in the function of yeast Gcn5p bromodomain: evidences from Molecular Dynamics and experiments”, Journal of Molecular Recognition, 19, 1, (2006)
Books
B1) “Molecular Dynamics Simulation of Statistical Mechanical Systems.”, ‘E. Fermi’ 1985 Summer School. G.Ciccotti and W.G.Hoover, Eds., North Holland 1986.
B2) “Simulation of Liquids and Solids. Molecular Dynamics and MonteCarlo methods in Statistical Mechanics. A reprint book.”, G. Ciccotti, D. Frenkel and I. R. Mc Donald, Eds. North Holland, 1987.
B3) “MC and MD of condensed matter systems”, Euroconference 1995, K. Binder and G. Ciccotti, Eds., SIF 1996.
B4) “Simulation of classical and quantum dynamics in condensed phase”, Euroconference 1997, B. J. Berne, G. Ciccotti and D. F. Coker, Eds., World Scientific, 1998.
B5) “Bridging time scales: Molecular simulations for the next decade”, SIMU Conference, Konstanz 2001, P. Nielaba, M. Mareschal, and G. Ciccotti, Eds., Springer, Berlin, 2003
B6) “Computer Simulations in Condensed Matter: From Materials to Chemical Biology (The Erice Lectures)”, M. Ferrario, G. Ciccotti, and K. Binder, Eds, LNP, Springer Verlag, Berlin, (2006)
Laser assisted fabrication of biomolecular sensing microarrays
The Pulsed Laser Deposition technique is used in these experiments in conjunction with micro and nanopatterning techniques to produce very high density arrays of localized active biomolecular layers. Such patterned layers of homogeneous or heterogeneous biomolecules are particularly interesting for the accomplishment of high density biosensing arrays.
Dr Pietro Morales
Contact Details
Sezione FIM MATNANO
Bldg. F65, Centro Ricerche della Casaccia, ENEA
Via Anguillarese km 1.3
00123 S.Maria di Galeria, Roma
Tel: +39 06 30486350
Lab: +39 06 30486082
Research Activity
From his first interest in molecular spectroscopy, which he pursued at the University La Sapienza in Roma, at the University of Venice and at the University of Kent UK, PM moved to spectroscopic applications in the field of uranium isotope separation, on which he worked up to the end of the italian laser isotope separation project led by ENEA. More recently he developed an interest in micro and nanobioscience and in nanotechnologies. From 1997 to 2000 he was the european coordinator of the LASMEDS project, devoted to the development of a molecular electronics technology that exploits vapour phase photoionization in the near field of STM probes. Later he coordinated and was involved in other national projects on nanotechnology, nanobioscience and organic devices. His present interests are in nanofabrication following both the inorganic, machine assisted, and the biological selfassembling approaches.
Recent Publications
[1] S. Gagliardi, B. Rapone, L. Mosiello, D. Luciani, A. Gerardino, P. Morales, Laser-Assisted Fabrication of Biomolecular Sensing Microarrays, IEEE Transactions on Nanobioscience, 6 (3): 242 – 248 (2007)
[2] A. Dell’Aquila, P. Mastrorilli, C.F. Nobile, G. Romanazzi, G.P. Suranna, L. Torsi, M.C. Tanese, D. Acierno, E. Amendola, P. Morales, Synthesis and field-effect properties of alpha,omega-disubstituted sexithiophenes bearing polar groups, Journal of Materials Chemistry, 16 (12): 1183-1191 (2006)
[3] S. Gagliardi, S. Nufris B. Rapone, P. Morales, G. D’Agostaro, Laser techniques for the fabrication of nanobiodevices, Proceedings of SPIE - The International Society for Optical Engineering, 5850, pp. 271-279 (2004)
[4] T. Di Luccio, G. Scalia, L. Tapfer, P. Morales, M. Traversa, P. Prete, N. Lovergine, Microstructural and morphological properties of homoepitaxial (001) ZnTe layers investigated by x-ray diffuse scattering,
Journal of Applied Physics, 97 (8): Art. No. 083540 (Apr 15 2005).
[5] I. Dierking, G. Scalia, P. Morales, Liquid crystal-carbon nanotube dispersions, Journal of Applied Physics, 97 (4): Art. No. 044309 (Feb 15 2005).
[6] M. Traversa, N. Lovergine, P. Prete, G. Scalia, M. Pentimalli, L. Tapfer, P. Morales, A.M. Mancini, Effects of substrate treatment and growth conditions on structure, morphology, and luminescence of homoepitaxial ZnTe deposited by metalorganic vapor phase epitaxy, Journal of Applied Physics, 96 (2): 1230-1237 (Jul 15 2004).
[7] P. Morales, Laser assisted SPM nanofabrication, in Encyclopaedia of Nanoscience and Nanotechnology, American Scientific Publishers, (Jan. 2004).
[8] I. Dierking, G. Scalia, P. Morales, D. LeClere, Aligning and reorienting carbon nanotubes by nematic liquid crystals, Advanced Materials, 16 (11) 865-869 (Jun 4 2004).
[9] A. Gerardino, A. Notargiacomo, P. Morales, Laser assisted deposition of nanopatterned biomolecular layers, Microelectronic Engineering, 67-8: 923-929 (Jun 2003).
3D Polymeric Scaffolds For Soft Tissue Engineering
Tissue engineering emerged in the early 1990s to address limitations of organ transplantation and synthetic tissue replacements, focusing on coupling cells and a biocompatible matrix known as a scaffold [1]. Since then, some clinical success has been obtained for hard tissues, such as bones and cartilages [2], and for bidimensional soft tissue, such as…
Nanocomposites Electrolytes for Intermediate Temperature Polymer Electrolyte Fuel Cells
Among the possible systems investigated for energy production with low environmental impact, fuel cells are very promising as electrochemical power sources both for stationary energy production and application in portable technology and electric vehicles. Polymeric electrolyte membrane fuel cells (PEMFCs) are the most promising candidates for the latter application.
Wetting Layer erosion during formation of InAs/GaAs(001) Quantum Dots
One of the puzzling aspects of the self-assembled QDs is that the nucleated 3D volume is far larger than that being deposited in the narrow coverage range where the entire nucleation process is completed. Resercher from NAST Centre have studied a peculiar feature, recently discovered [1], at the origin of this phenomenon, which is associated with mature 3D QDs,…
Scanning Electron Microscopy (SEM) and Energy Dispersive X-Ray Spectrometry (EDS)
LEO 35 Field Emission by Zeiss©
Characteristics
• GEMINI® based Field emission e-beam column capable of ultra high resolution SEM up to 25 KV.
• Achieves a similar low energy spread compared to a cold field emission source, but with a much higher emission current and much higher beam stability.
• Featuring a TV camera and three detectors, i.e. (i) secondary electrons detector, (ii) back-scatter electrons detector (EBSD) , (iii) In-lens detector for ultra high resolution imaging (<10nm).
• Equipped with an energy dispersive x-Ray spectrometer (EDS) from Oxford INCA© allowing for acquisition of sample emitted x-rays. Accompanying software with embedded database of reference spectra for elements identification/recognition, compositional nano-analysis and x-ray mapping.
• Automated stage controlled by a joystick with x-y-z translations, z rotation (full 360° range) and x tilting (up to 90° tilt) for ultra high precision sample positioning.
• Vacuum system (a rotary pump plus a turbo pump) to achieve chamber vacuum of less than 2 x 10-6 mbar.
• Dynamic vibration-damper.
• Several stubs settings and adaptors for mounting samples on the stage.
• Sample preparation desk.
• Sputter-coater to metallize non-conductive samples (with gold or other target).
Some Results
SEM is a common tool to address a variety of aspects in material research and nanotechnology. For illustrative purposes, some examples of SEM work in a variety of research areas (e.g energy, environment, biotechnology and nanotechnology in general) are reported here. As far as energy and environment are concerned, ceramics and nanostructured materials are key in applications such as fuel cells and chemical sensors. Fig.1 shows a surface micrograph of a composite porous electrode (cathode) designed for Solid Oxide Fuel Cell applications and fabricated by Pulsed Laser Deposition technique. Pd-Au metal droplets have been deposited and condensed on a continuous open La0.8Sr0.2Co0.8Fe0.2O3-δ network, previously grown on a dense polycrystalline stabilized ZrO2. Mixed ionic and electronic properties of La0.8Sr0.2Co0.8Fe0.2O3-δ assisted by the electrical properties of metal droplets at high temperature, reduce the cathode polarization in SOFCs.
Figure 1. Surface of a composite porous electrode (cathode) designed for SOFC applications and fabricated by Pulsed Laser Deposition technique. Pd-Au metal droplets were deposited onto a continuous open La0.8Sr0.2Co0.8Fe0.2O3-δ network grown on dense polycrystalline stabilized ZrO2.
Another class of fuel cells are based on the usage of polymeric “Proton Exchange Membranes” (PEM) as the fuel cell electrolyte. Nafion is the best performing polymer currently available for this application but, amongst other drawbacks, suffers of a marked drop in conductivity for working temperatures above 90°C due to morphological transitional and de-hydration. A variety of composite membrane, i.e. hybrid structures of Nafion with dispersed fillers, are under investigation to overcome this problem. Figure 2 shows an example of Nafion mixed with an inorganic phase “sulfonate diphenyl silane diol” (SDPSD), appearing as “bright” islands in the photos. The PEM performances improve based on the content and distribution of the SDPSD. Thermal treatment is one way of controlling the microstructure of the composite structure. SEM micrographs clearly shows that heating the samples at 170 °C induces a finer dispersion of the filler, yielding more minute SDPSD clusters. The limited electronic conductivity of this material makes it difficult to analyze with the SEM.
Figure 2. Two SEM pictures of the Nafion/SDPSD 70:30 composite membrane for PEM fuel cells. Photos selected demonstrate the effect of the thermal treatment at 170°C on the dispersion SDPSD in the microstructure. Sample “as-prepared” (far left) and the “heat-treated” one (left) exhibit different dispersion of SDPSD islands within the Nafion matrix, highlighting a size reduction of the SDPSD clusters induced by the thermal treatment.
SEM imaging is also crucial for the characterization of nanostructured materials for biological applications. Within biotechnology, tissue engineering combines the fields of engineering, chemistry, biology, and medicine to fabricate replacement tissues able to restore, maintain, or improve structurally and functionally damaged organs. Polymeric scaffolds for stem cells growth and differentiation represent an active research topic. Some scaffolds are fabricated by electrospinning as highly interconnected porous polymeric networks. Figure 3 shows a SEM image of nanostructured PLA electrospun nanofibers endowed with nanopores. Such fibres are multiscale features, having lengths in the centimetre range, micrometric and sub-micrometric diameters and nanoscale roughness/porosity. The various length-scales can be largely tuned and tailored through processing parameters.
Figure 3. SEM image of PLA electrospun nanofibers with nanopores. The fibres have a multiscale geometry with lengths in the centimetre range, diameters between few tens of nanometers and few micrometers, and nanoscale porosity. Length-scales can be tuned and tailored through processing parameters. Controlled porosity is important also for drug delivery.
The topics briefly highlighted in the examples are discussed in greater details in several papers. The interested reader can consult the selected papers cited in the reference.
SEM capabilities go beyond pure geometrical and morphological information, highlighted in the previous examples. In fact backscattered electrons and EDS can be used to obtain compositional data. In the next example in Figure 4, a carbon nanoparticle of about 400 nm deposited from the environment onto a substrate made of nanoporous Si. The X-ray spectra shown on the left were collected with the EDS at two different locations pointed out in the SEM micrograph, i.e. at point (1) centered on the nanoparticle and at point (2) away from it. From comparison, the missing peak in the spectrum collected at site (2) is characteristic of C, which reveals the chemical nature of the nanoparticle.
Figure 4: Micro-analisys by EDS of a 400nm carbon particle (site 1) deposited from the environment onto a nanoporous Si substrate. The nature of the nanoparticle is highlighted as a “difference”, because the yellow spectrum at site (2) is missing a peak characteristic of carbon and present in the red spectrum at site (1).
References on SOFC and PEM
[1] D. Z. de Florio, R. Muccillo, V. Esposito, E. Di Bartolomeo and E. Traversa, “Preparation and Electrochemical Characterization of Perovskite/YSZ Ceramic Films”, J. Electrochem. Soc., 152 (1), A88, (2005).
[2] V. Esposito, D. Z. de Florio, F.C. Fonseca, E.N.S. Muccillo, R. Muccillo and E. Traversa, “Electrical properties of YSZ/NiO composites prepared by a liquid mixture technique”, J. Eur. Ceram. Soc., 25, 2637, (2005).
[3] Deganello, V. Esposito, E. Traversa and M. Miyayama. “Cathode performance of nostructured La1-aSraCo1-bFebO3-d on a Ce0.8Sm0.2O2 electrolyte prepared by citrate-nitrate auto-combustion”, F J. Electrochem. Soc., 154 (2), A89, (2007).
[4] Barbara Mecheri, Alessandra D’Epifanio, Enrico Traversa, Silvia Licoccia. “Effect of an ormosil-based filler on the physico-chemical and electrochemical properties of Nafion membranes”, J. Power Sources, 169 (2007) 247–252.
References on Chemical Sensors
[5] M.L. Grilli, E. Di Bartolomeo, A. Lunardi, L. Chevallier, S. Cordiner and E. Traversa, “Planar Non-Nernstian electrochemical sensors: field test in the exhaust of a spark ignition engine”. Sensors and Actuators B, 108 (2005) 319-325
[6] L. Chevallier, M.L. Grilli, E. Di Bartolomeo and E. Traversa. “Non-Nernstian planar sensors based on YSZ with Ta (10 at.%)-doped nanosized titania as sensing electrode for high temperature applications”. International Journal of Applied Ceramic Technology, 3 [5] 393-400 (2006)
References on Tissue Engineering
[7] E. Traversa, B. Mecheri, C. Mandoli, S. Soliman, A. Rinaldi, S. Licoccia, G. Forte, F. Pagliari, S. Pagliari, F. Carotenuto, M. Minieri, P. Di Nardo. “Tuning Hierarchical Architecture of 3D Polymeric Scaffolds for Cardiac Tissue Engineering”, J. Exp. Nanoscience, (accepted sept. 2007).
Prof. Silvia Morante
Contact Details
Office: Physics Department
Tel: +39 06 72594554
Fax: +39 06 2023507
Research Activity
- Folding versus misfolding: physiological and pathological role of metal
- The role of metals in neurodegenerative diseases – Alzheimer, BSE and Parkinson
- Structural studies of biomolecules by XAS (X-ray Absorption Spectroscopy)
- Numerical simulation based approaches (Molecular Dynamics, Monte Carlo, Car-Parrinello)
Recent Publications
[1] V. Minicozzi, S. Morante, G.C. Rossi, F. Stellato, K. Jansen, The role of metals in misfolding and aggregation processes: X-ray spectroscopy and numerical simulations, in From Computational Biophysics to System Biology (CBSB07), Proceedings of the NIC Workshop 2007, 36: 223
[2] S. Furlan, F. Guerrieri, G. La Penna, S. Morante, G.C. Rossi, Studying the Cu binding sites in the PrP N-terminal region. A test case for ab initio simulations, European Biophysics Journal, 36: 841-845 (2007)
[3] S. Furlan, G.La Penna, F. Guerrieri, S. Morante, G.C.Rossi, Ab initio simulations of Cu binding sites on the N-terminal region of PrP, Journal of Biological Inorganic Chemistry, 12(4), 571-583, (2007)
[4] S. Furlan, F. Guerrieri, G.La Penna, S. Morante, G.C. Rossi, Ab initio simulations of Cu binding sites in the N-terminal region of PrP, in From Computational Biophysics to System Biology, J. Meinke, O. Zimmermann, S. Mohanty, U.H.E.Hansmann (Editors) John von Neumann Institute for Computing, Juelich, NIC Series, 34, 153-156, (2006).
[5] S. Morante, G. C. Rossi, M. Testa, The stress tensor of a discrete system: an exercise in Statistical Mechanics, J. Chem. Phys., 125, 034101 (2006).
[6] F. Stellato, G. Menestrina, M. Dalla Serra, C. Potrich, R. Tomazzolli, W. Meyer-Klaucke, S. Morante, Metal binding in amyloids beta peptides shows both intra- and inter-peptide coordination modes, European Biophysics Journal, 35(4), 340 (2006).
[7] S. Morante, C. Poltrich, R. González-Iglesias, C. Meneghini,W. Meyer-Klaucke, G. Menestrina, M. A. Pajares, M. Gasset, Inter- and Intra-octarepeat Cu(II) Site Geometries in the Prion Protein. Implication in Cu(II) binding cooperativity and Cu(II)-mediated assemblies, J. Biol. Chem. 279, 11753 (2004).
[8] G. La Penna, S. Morante, A. Perico, G.C. Rossi, Designing generalized statistical ensembles for numerical simulations of biopolymers, J. Chem. Phys., 121, 10725 (2004).
[9] M. Benfatto, S. Della Longa, Z. Wu, Y. Qin, G. Pan, S. Morante, The role of Zn in the interplay among Langmuir-Blodgett Multi-Layer and Myelin Basic Protein: a quantitative analysis of XANES spectra, Biophysical Chemistry, 110, 191 (2004).
[10] G. La Penna, V. Minicozzi, S. Morante, G.C. Rossi, Tuning force-field parameters by pressure measurements in micro-canonical simulations, International Journal of Modern Physics C., 15, 205 (2004).
Prof. Lorenzo Stella
Contact Details
Office: Department of Science and Chemical Technologies
Tel: +39 06 72594463
Fax: +39 06 72594328
Research Activity
- 3-D structures of peptides in solution
- Peptide-membrane interactions
- Biomolecular electronics
- Molecular recognition and chiral discrimination
- Computational chemistry and molecular modeling
Recent Publications
[1] L. Stella, G. Bocchinfuso, E. Gatto, C. Mazzuca, M. Venanzi, F. Formaggio, C. Toniolo, A. Palleschi and B. Pispisa. “Peptide foldamers: from spectroscopic studies to applications”. Reviews in Fluorescence 2007. C. D. Geddes and J. R. Lakowicz (Eds.), Springer, New York, (2007).
2] E. Gatto, C. Mazzuca, L. Stella, M. Venanzi, C. Toniolo, B. Pispisa. “Effect of peptide lipidation on membrane perturbing activity: a comparative study on two trichogin analogues”. J. Phys Chem. B., 110: 22813 (2006).
3] M. Venanzi, E. Gatto, G. Bocchinfuso, A. Palleschi, L. Stella, C. Baldini, F. Formaggio, C. Toniolo. ”Peptide folding dynamics: a time-resolved study from the nanosecond to the microsecond time regime”. J. Phys. Chem. B, 110: 22834 (2006).
4] B. Pispisa, L. Stella, C. Mazzuca, M. Venanzi. “Trichogin topology and activity in model membranes as determined by fluorescence spectroscopy” . Reviews in fluorescence 2006, C. D. Geddes and J. R. Lakowicz (Eds.), Springer, New York, pp. 47 (2006).
5] E. Gatto, M. Venanzi, A. Palleschi, L. Stella, B. Pispisa, L. Lorenzelli, C. Toniolo, F. Formaggio, G. Marletta. ”Self-assembled peptide monolayers on interdigitated gold microelectrodes” . Mat. Sci. Eng. C., 26: 918 (2006).
6] C. Carta, F. Pantaleoni, G. Bocchinfuso, L. Stella, I. Vasta, A. Sarkozy, C. Digilio, A. Palleschi, A. Pizzuti, P. Grammatico, G. Zampino, B. Dallapiccola, B. D. Gelb, M, Tartaglia. “Germline missense mutations affecting KRAS isoform B are associated with a severe Noonan syndrome phenotype” . Am. J. Hum. Gen., 79: 129 (2006).
Prof. Nicola Rosato
Contact Details
Office: Department of Experimental Medicine and Biochemical Sciences
Tel: +39 06 72596471
Fax: +39 06 72596465
Research Activity
Fields of interest: structure and function of biological macromolecules under high pressure and electromagnetic field. Application of optical spectroscopy and Near Infrared Spectroscopy “in vivo”. Smart nanomaterials in biology and medicine. From 1991 is a member of the commission for the medical application of informatics at the Medical School of the “Tor Vergata” University. From March 2000, is Full Professor in Biochemistry in the Faculty of Medical EngineeringFrom December 2002 is director of the Medical Engineering Service in the “Tor Vergata” University Hospital.N. Rosato is author of about 70 scientific publications (60 on international journals) in the fields of optical spectroscopy of biological molecules, fluorescence instrumentation and medical informatics.
Recent Publications
[1] Bottini M, D’Annibale F, Magrini A, Cerignoli F, Arimura Y, Dawson MI, Bergamaschi E, Rosato N, Bergamaschi A, Mustelin T., “Quantum dot-doped silica nanoparticles as probes for targeting of T-lymphocytes”, Int. J. Nanomedicine, 2(2):227-33, (2007)
[2] Bottini M, Cerignoli F, Tautz L, Rosato N, Bergamaschi A, Mustelin T., “Adsorption of streptavidin onto single-walled carbon nanotubes: application in fluorescent supramolecular nanoassemblies”, J. Nanosci. Nanotechnol. 6(12), 3693-8 (2006)
[3] Nicolai E, Di Venere A, Rosato N, Rossi A, Finazzi Agro’ A, Mei G., “Physico-chemical properties of molten dimer ascorbate oxidase”, FEBS J. , 273(22):5194-204. (2006)
[4] Iucci G, Rossi L, Rosato N, Savini I, Duranti G, Polzonetti G., “The interaction of the polyphenylacetylene surface with biological environments studied by XPS, RAIRS and biological tests”, J Mater Sci Mater Med. 17(9):779-87, (2006)
[5] Bottini M, Cerignoli F, Dawson MI, Magrini A, Rosato N, Mustelin T., “Full-length single-walled carbon nanotubes decorated with streptavidin-conjugated quantum dots as multivalent intracellular fluorescent nanoprobes”, Biomacromolecules, 7(8):2259-63, (2006)
[6] Bottini M, Magrini A, Rosato N, Bergamaschi A, Mustelin T., “Dispersion of pristine single-walled carbon nanotubes in water by a thiolated organosilane: application in supramolecular nnoassemblies”, J Phys Chem B.,20; 110 (28) : 13685-8, (2006)
[7] Bottini M, Magrini A, Di Venere A, Bellucci S, Dawson MI, Rosato N, Bergamaschi A, Mustelin T. “Synthesis and characterization of supramolecular nanostructures of carbon nanotubes and ruthenium-complex Luminophores”, J Nanosci Nanotechnol., 6(5):1381-6, (2006)
[8] Mei G, Di Venere A, Rosato N, Finazzi-Agro A., “The importance of being dimeric”, FEBS J., 272(1):16-27, (2005), Review.
[9] Iucci G, Infante G, Rossi L, Polzonetti G, Rosato N, Avigliano L, Savini I, Catani MV, Palacios AC., “Albumin-containing sol-gel glasses: chemical and biological study”, J Mater Sci Mater Med., 15(5):601-6, (2004)
Education
The NAST mission is to serve the next generation of researchers in nanotechnology at the Bachelor, Master, PhD, and Postdoctoral levels.
PhD Schools
PhD Program in Nanostrucutres and Nanotechnologies
a Joint Program between Università degli Studi di Milano Bicocca and Università degli Studi di Roma Tor Vergata
Ph.D. Program in Materials for Environment and Energy
a Joint Ph.D. Program with The University of Tokyo, Research Center for Advanced Science and Technology and The University of Florida, Department of Materials Science and Engineering.
PhD Program in Physics
in collaboration with Physics Department, Università degli Studi di Roma Tor Vergata
Schools
1st Doctorate School in Nano - Materials & Biomaterials (May 2007) Group Photo
Prof. Giuseppe Gorini
Contact Details
Office: Università degli Studi di Milano Bicocca, Piazza della Scienza 3, Milano
Tel: +39 02 6448 2312
Academic career
1986 - 1988 Phd student, Scuola Normale Superiore - Pisa
1989 - 1990 Researcher, IFP-CNR, Milan
1990 - 1998 Researcher, Universita’ degli Studi di Milano
1998 - 2000 Researcher, Universita’ degli Studi di Milano-Bicocca
2000 - present Associate Professor, Universita’ degli Studi di Milano-Bicocca
Research Activity
Neutron spectroscopy in thermonuclear plasmas.
Neutron spectroscopy for materials science
Physics of high temperature plasmas
Application of neutron-based techniques to Cultural Heritage research
Teaching
Electromagnetism and optics, degree in Environmental Science.
Physics of Plasmas, degree in Physics.
Supervisor of undergraduate and Ph D students in Physics.
Recent Publications
[1] G. Gorini et al, The resonant detector and its application to epithermal neutron spectroscopy, Nucl. Instr. and Meth. A, 529, 293 (2004).
[2] C. Andreani, G. Gorini, E. Perelli-Cippo, A. Pietropaolo, N. Rhodes, E. S. Schooneveld, R. Senesi, M. Tardocchi, A resonant detector for high-energy inelastic neutron scattering experiments, Appl. Phys. Lett., 85, 5454 (2004).
[3] J Källne, L Ballabio, J Frenje, S Conroy, G Ericsson, M Tardocchi, E Traneus, G.Gorini, Observation of the Alpha Particle “Knock-On” Neutron Emission from Magnetically Confined DT Fusion Plasmas, Phys Rev Lett., 85, 1246 (2000).
[4] G.Gorini, P.Mantica, G.M.D.Hogeweij, F.De Luca, A.Jacchia, J.A.Konings, N.J.Lopes Cardozo, M.Peters, Simultaneous Propagation of Heat Waves Induced by Sawteeth and ECH Power Modulation in the RTP Tokamak, Phys. Rev. Lett., 47, 2038 (1993).
Prof. Silvia Licoccia
Contact details
Office: Department of Chemical Science and Technology
Tel: +39 06 72594386
Lab: +39 06 72594479
Fax: +39 06 72594328
Research Activity
SL is Professor of Chemistry in the Faculty of Engineering of the University of Rome Tor Vergata.
Active Member of The Materials Research Society of The International Sol-Gel Society. Secretary of the Board of Directors of AICIng (Italian Association of Chemistry for Engineering), Member of the Executive Committee of The Electrochemical Society.
SL Research activity is mainly focused on the following topics:
• Development of nanostructured materials for Polymeric and Solid Oxide Fuel Cells and for gas sensors for environmental monitoring.
• Synthesis and spectroscopic characterization of new materials for energy, environmental and biomedical applications.
• Multinuclear NMR spectroscopy and its application to kinetic and structural studies.
• Synthesis, reactivity and study of the spectroscopic properties of transition metal complexes of tetrapyrrolic macrocycles. Investigation of the electronic and molecular structure of paramagnetic derivatives by means of NMR spectroscopy.
SL is co-author of 145 refereed scientific publications (115 on international Journals) and about 190 scientific oral contributions at international conferences, meetings and schools.
Active Research Programs
• FISR NUME Project: Development of composite proton conducting membranes and new electrode configurations for PEMFC applications (http://www.progetto-nume.it/) Partners: U. of Rome ‘La Sapienza’, U. of Genoa, U. of Camerino, U. of Pavia, U. of Bologna, U. of Perugia, U. of Padua, CNR, CRS4
• FISR Project: Polymeric and Ceramic Fuel Cells: systems demonstrators and development of new materials. Partners: CNR-ITAE, INSTM, Enitcnologie S.p.A., ENEL S.p.A., Nuvera Fuel Cells Europe s.r.l., De Nora tecnologie Elettrochimiche s.r.l.
• PRIN: Preparation and characterization of hybrid organic-inorganic materials by assembling of nano-building block. Partners: U. of Trento, U. di Padua, U. Sassari, U. Campus Biomedico
• PRIN: Protonic ceramics for Fuel Cells Partners: U. of Palermo, U. of Reggio Calabria, U. of Cassino, U. of Genoa
• EU Project CARISMA: Coordination Action for Research on Intermediate and high temperature Specialised Membrane electrode Assemblies. A network of research activities in Europe on high temperature membrane electrode assemblies and their components. Coordination activities are centered around membranes, catalysts and high temperature MEAs, with cross-cutting activities on the impact of high temperature operation on degradation of MEA components and MEA durability, identification of proton transfer mechanisms operating in water free conditions, and technical specifications for high temperature PEMFC applications. The CARISMA partnership assembles the expertise in high temperature PEMFC in European research institutes and universities and includes committed stakeholders and industrial developers.
Other Activities
Co-organizer of different conferences and symposia under the frame of the MRS, Electrochemical Society and of The European Ceramic Society meetings.
Teaching
Chemistry 1, Faculty of Engineering, Chemistry 3, Faculty of Engineering ,Environmental Monitoring, Faculty of Engineering
Member of the Teaching Supervising Committee of the International Ph.D. Program in Materials for Environment and Energy, a Joint Ph.D. Program with The University of Tokyo, Research Center for Advanced Science and Technology and The University of Florida Department of Materials Science and Engineering.
Recent Publications (selected)
[1] B. Mecheri, A. D’Epifanio, M. L. Di Vona, E. Traversa, S. Licoccia, M. Miyayama, “Sulfonated polyether ether ketone-based composite membranes doped with a tungsten-based inorganic proton conductor for Fuel Cell applications, Journal of Electrochemical Society, 153, A463-A467 (2006).
[2] F. A. Walker, S. Licoccia, R. Paolesse, “Iron Corrolates: Unambiguous Chloroiron(III) (Corrolate)2–• π-Cation Radicals”, Journal of Inorganic Biochemistry, 100, 810 - 837 (2006).
[3] S. Licoccia, M. L. Di Vona, P. Romagnoli, L. Narici, M. Acquaviva, S. Carozzo, S. Di Marco, M. Saturno, W. G. Sannita, E. Traversa, “Nanocomposite polymeric electrolytes to investigate human electrophysiological brain signals in prolonged, unconventional or extreme conditions”, Acta Biomaterialia, 2, 531-536 (2006).
[4] S. Licoccia, E. Traversa, “Increasing the operation temperature of Polymer Electrolyte Membranes for Fuel Cells: from nanocomposites to hybrids”, Journal of Power Sources, 159, 12-20 (2006).
[5] A. Rainer, F. Basoli, S. Licoccia. E. Traversa, “Foaming of filled polyurethanes for fabrication of Porous Anode Supports for Intermediate Temperature Solid Oxide Fuel Cells (IT-SOFCs)”, Journal of The American Ceramic Society, 89 [6], 1795-1800 (2006).
[6] S. Licoccia, M. L. Di Vona, A. D’Epifanio, Z. Ahmed, S. Bellitto, D. Marani, B. Mecheri, C. de Bonis, M. Trombetta, E. Traversa, “SPPSU-Based Hybrid Proton Conducting Polymeric Electrolytes For Intermediate Temperature PEMFCs”, Journal of Power Sources, 167, 79-83 (2007).
[7] B. Mecheri, A. D’Epifanio, E. Traversa, S. Licoccia, “Effect of an ormosil-based filler on the physico-chemical and electrochemical properties of Nafion membranes”, Journal of Power Sources, 167, 247-252 (2007).
[8] A. D’Epifanio, B. Mecheri, E. Fabbri, A. Rainer, E. Traversa, S. Licoccia, “Composite Ormosil/Nafion Membranes As Electrolytes For Direct Methanol Fuel Cells”, Journal of The Electrochemical Society, 154, 1-4 (2007).
Ultra-high dense growth of germanium nanodots on SiO2 thin films
The use of self-organization phenomena at semiconducting surfaces allows fabricating quantum dot structures for producing novel nanodevices with unprecedented applications not only in optoelectronics, but also for room temperature operating single electron transistors and/or resonant tunneling structures. Fabrication of ultra-dense Ge dots on silicon surfaces still presents a series of problems far …
18/09/2007, The Icing on the Cake - Combining X-Ray Absorption Spectroscopy with Protein Crystallography
Dr. W. Meyer-Klaucke
Nanoengineered silica nanoparticles as intracellular nanoprobes
Nanotechnology is the science of manipulating matter at the atomic and molecular level to obtain materials with specifically enhanced chemical and physical properties. Collaborative research among scientists from Italy - the Nast Centre for Nanoscience Nanotechnology and Innovative Instrumentation, are working in the emerging challanging field of nanomedicine…
Prof. Maurizio De Crescenzi
Contact details
Office: Physics Department
Tel: +39 06 72594547
Lab: +39 06 72594532
Fax: +39+06 2023507
Research Activity
From 1979 his research activity has been focused on the study of the structural and electronic properties of surfaces (clean and interacting with chemisorbed species), and of metal/semiconductor interfaces by means of spectroscopic techniques such as Auger, XPS and Energy Loss in reflection and STM (Scanning Tunneling Microscopy) microscope.
During these years he has contributed actively to the development of some electron spectroscopic techniques as local surface structural tool, as the EELFS (Extended Energy Loss Fine Structure) and the EXFAS (Extended Fine Auger Structure). He has received for this several invited talks and oral presentations at topic Surface Science Conferences.
He has investigated the growth of nanostructures of Germanium/Silicon and Fe/Cu/Si ultrathin films through MBE process. Recently he has synthetized nanotubes of carbon and other materials, such as silicon, and they have been visualized through STM and AFM microscopy.He has been co-author or author of more than 200 international publications concerning electronic and structural properties of the condensed matter and applications of different electron scattering and absorption spectroscopies. He has written a book entitled: ”Electron Scattering and Related Spectroscopies” (World Scientific 1996) providing an overview of all spectroscopic techniques related to electron scattering phenomena. He is in the board of editors of the following international reviews: Journal of Physics (Condensed Matter), Surface Review and Letters, Journal of Electron Spectroscopy.
Recent Publication
[1] P. Castrucci, N. Pinto, L. Morresi, R. Gunnella, R. Murri, M. Scarselli, M. De Crescenzi, “Magnetic properties of thin MnGe films investigated by magnetic force microscopy”, Journal of Magnetism and Magnetic Materials 272-276, 1541 (2004).
[2] F. Ratto, F. Rosei, A. Locatelli, S. Cherifi, S. Fontana, S. Heun, P.-D. Szkutnik, A. Sgarlata, M. De Crescenzi, N. Motta, “Composition of Ge(Si) islands in the growth of Ge on Si(111) by x-ray spectromicroscopy”, Journal of Applied Physics 97, 043516 (2005).
[3] M. De Crescenzi, P. Castrucci, M. Scarselli, M. Diociaiuti, P. S. Chaudari, C. Balasubramanian, T. M. Bhave, S. V. Bhoraskar, “Experimental images of silicon nanotubes”, Applied Physics Letters 86, 231901 (2005). Paper selected to appear on June 1, 2005 of “Virtual Journal of Nanoscale Science & Technology“.
[4] P. Castrucci, M. Scarselli, M. De Crescenzi, M. Diociaiuti, P. Chistolini, M. A. El Khakani, F. Rosei, “Packing-induced electronic structure changes in bundled single-wall carbon nanotubes”, Applied Physics Letters 87, 103106 (2005).
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10/09/2007, Cell Sheet Tissue Engineering and Their Clinical Applications
Prof. Teruo Okano
Mean Kinetic Energy in Helium mixtures and nanoporous confinement
Collaborative research among scientists from Italy - the Nast Centre for Nanoscience Nanotechnology and Innovative Instrumentation, UK - ISIS Spallation Neutron Source - have studied the single particle microscopic dynamics of helium atoms (3He, 4He) in bulk and confined in silica nanopores, using Deep Inelastic Neutron Scattering (DINS) at the ISIS…
Dr. Roberto Senesi
Contact details
Office: Department of Physics
Tel: +39 06 72594549
Fax: +39 06 2023507
R. Senesi is an experimental physicist with a background in condensed matter and material science. The main Research Topics are: Neutron Scattering, Monoatomic and Molecular Quantum Fluids and solids in bulk and confinement. Experimental determination of the atomic momentum distributions and microscopic structure and dynamics of these systems are carried out using neutron scattering and x-ray and techniques. Relevant examples are: 1) Momentum distribution and kinetic energy in fluid and solid He-3, He-4 and He-3/He-4 mixtures; 2) Kinetic energy of He-4 in nanoporous xerogels; 3) Static structure factor of binary fluid mixtures. R. Senesi has been involved in the design and construction of neutron scattering instruments at the ISIS pulsed neutron facility (UK), such as VESUVIO and e.VERDI, as well as research and development of neutron detection systems for neutrons in the energy range 1- 100 eV. R. Senesi has published more than 60 papers on international journals and presented about 20 scientific contributions at international conferences and schools.
Recent Publications
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R. Senesi, A. Pietropaolo, A. Bocedi, S. E. Pagnotta, F. Bruni, Proton Momentum distribution in a protein hydration shell, Physical Review Letters, 98, 138102 (2007), also in Virtual Journal of Biological Physics Research, 13, issue 7 (2007).
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R. Senesi, D. Colognesi, A. Pietropaolo, T. Abdul-Redah, Deep inelastic neutron scattering from orthorhombic ordered HCl: short-time proton dynamics and anomalous neutron cross-sections, Physical Review B, 72, 054119 (2005).
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C. Andreani, D. Colognesi, J. Mayers, G. Reiter, R. Senesi, Measurement of Momentum Distribution of Light Atoms and Molecules in Condensed Matter Systems Using Inelastic Neutron Scattering, Advances in Physics, 54, 377 (2005).
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C. Andreani, G. Gorini, E. Perelli-Cippo, A. Pietropaolo, N. Rhodes, E. M. Schooneveld, R. Senesi, M. Tarocchi, A resonant detector for high-energy inelastic neutron scattering experiments, Applied Physics Letters, 85, 5454, (2004).
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C. Andreani, C. Pantalei, R. Senesi, Mean kinetic energy of helium atoms in fluid 3He and 3He-4He mixtures, Journal of Physics: Condensed Matter, 18, 5587 (2006).
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R. Senesi, C. Andreani, A. L. Fielding, J. Mayers, W. G. Stirling, Kinetic energy of He atoms in liquid 4He-3He mixtures, Physical Review B, 68, 214522 (2003).
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R. Senesi, C. Andreani, D. Colognesi, A. Cunsolo, M. Nardone, Deep Inelastic Neutron Scattering determination of the single particle kinetic energy in solid and liquid 3He Physical Review Letters, 86, 4584, (2001).
Dr Antonino Pietropaolo
Contact details
Physics Department “G. Occhialini”
University of Milan “Bicocca”
Tel: +39 02 6448 2302
Research activity
AP is an experimental physicist whose research interests concern the dynamics of condensed matter systems and the investigation of the high energy neutron-induced soft errors in electronics, using neutron scattering techniques, and the development of instrumentation for epithermal neutron scattering for applications on materials of cultural heritages interest (epithermal neutron imaging). As far as neutron instrumentation is concerned, AP worked on the development of gamma detectors for the Resonance Detector configuration at the VESUVIO spectrometer at ISIS spallation neutron source and the design and realization of the Very Low Angle Detector (VLAD) bang for High-energy Inelastic Neutron Scattering (HINS) on VESUVIO. In the field of condensed matter, recent experimental studies concerned the short time proton dynamics in bulk and confined water at different thermodynamic states, as well as the sub-femtosecond dynamical properties of the structural hydrogen (silanols) in porous silica xerogels of different porosity. Within the EU-funded ANCIENT CHARM project, AP is developing ancillary equipment and gamma detectors to be used for Neutron Resonance Capture Imaging (NRCI) and neutron tomography on objects of cultural and archaeological interest. A recent experimental activity is related to the test of the new Silicon Photomultiplier (SiPM) coupled to YAP scintillators crystals. Very recently AP, within a joint collaboration of Italian academic institutions and the Science and Technology Facilities Council (STFC), performed the first irradiation experiments on silicon-based Field Programmable Gate Arrays (FPGA) on the VESUVIO beam line, that assessed the suitability of the ISIS source for this kind of investigation.
Recent publications
- R.Senesi, A. Pietropaolo, A. Bocedi, S.E. Pagnotta, F. Bruni, Phys. Rev. Lett. 98, 138102 (2007);
- M. Violante, L. Sterpone, A. Manuzzato, S. Gerardin, P. Rech, M. Bagatin, A. Paccagnella, C. Andreani, G. Gorini , A. Pietropaolo, G. Cardarilli, S. Pontarelli, C. Frost, IEEE Trans. Nucl. Sci. 54, 1184 (2007);
- E. M. Schooneveld, J. Mayers, N. J. Rhodes, A. Pietropaolo, C. Andreani, G. Gorini, E. Perelli-Cippo, R. Senesi, M. Tardocchi, Rev. Sci. Instr. 77, 095103 (2006);
- S. Imberti, C. andreani, V. Garbuio, G. Gorini, A. Pietropaolo, R. Senesi, M. Tarocchi, Nucl. Instr. Meth. A 552, 463 (2005);
- C. Andreani, G. Gorini, E. Perelli-Cippo, A. Pietropaolo, N. Rhodes, E. M. Schooneveld, R.Senesi, M. Tardocchi, Appl. Phys. Lett. 75, 5454 (2004).
Notes: AP is author of about 40 publications on international journals and presented about 20 scientific contributions at international conferences and meetings.
NAST Report
Scientific Report 2007
Atomic Force Microscope (AFM) & Scanning Tunnelling Microscopy (STM)
The Variable Temperature STM/AFM
Characteristics
Stainless steel UHV system (Standard pressure 6 10-11mbar).Turbo molecular pump for roughing: 240 l/sec - Ionic pump: 500 l/sec - Titanium sublimator.X-Y-Z manipulator with direct current or resistive heating. Tmax=1500 K.STM/AFM (piezoresistive).Heating at the STM position: up to 1500 K.Cooling at the STM position: down to 25 K.E-beam evaporators at the STM position: Ge and Si.Reverse view LEED-Auger with LaB6 filament.
Some Results
Ge/Si(111) - experiments performed were related to the visualization of the growth by Physical Vapour Deposition of Ge nanostructures on 7×7 Si(111) reconstructed surfaces. By evaporating Ge on Si(111) at T=500°C the formation ofwetting layers have been studied by Scanning Tunneling Microscopy in situ. The evolution of the Ge islands appearing after the wetting layer (completed at 3 ML). The 3D islands appear as truncated tetrahedrons (7×7 reconstructed on the top) and evolves into rounded shape, flat islands with a central hole. An erosion of the substrate around the islands has been also evidenced and measured. The island have lateral dimensions in the range 200 - 500 nm. The statistical distribution of the islands shapes and contact angles has been analysed. On Si step bunched surfaces (obtained by flashing at 1200°C in proper condition the Si substrate) the self aggregation and ordering of the islands has been evidenced. These results have been published in several papers and conference or school proceedings [1-6].
Fig 1. Ge islands grown on Si(111) observed by STM and AFM at various stages of evolution. Top left, a) an island after the nucleation (STM: 236×236x8 nm), top rigth, b) new facets (100 and 117) appear (STM: 230×230x38 nm); bottom left, c). First stage of ripening. (STM: 527×527x12 nm) bottom rigth, d) final stage of ripening (AFM image: 527×527x10 nm). Ge flux was 1 Å/min. The substrate temperature was 530 °C for a), 450 °C for b) and 500 °C for c) and d).
Fig 2. Organization of the Ge islands on a Si(111) step-bunched substrate a) STM image of 2.5 nm Ge deposition on Si(111) at T=450 °C 2.7×3.7 μm2. The total height of the image is 56 nm. b) STM image of 6 nm Ge deposition on Si(111) at T=450 °C 10×10 μm2. The total height of the image is 82 nm.InAs/GaAs quantum dotsThe InAs quantum dots on GaAs were prepared ex-situ by MBE as follows: the GaAs(001) wafer was initially deoxidized in As flux at 640 °C until a weak 2×4 RHEED pattern appeared. Afterwards, the substrate temperature was lowered to 590 °C and an epitaxial GaAs buffer layer of approximately 0.75 mm was grown at a rate of 1 μm/h. After 10 min of annealing, the temperature was further lowered to 500 °C for the InAs growth. The deposition rate was 0.028 ML/s with an In/As flux ratio of 1/15. The InAs coverage was 3 ML (the 2D-3D transition occurs at 1.6 ML). A 50 nm As capping layer is grown on top of the quantum dots, in order to protect the surface during the transfer to the AFM/STM chamber if atomic resolution and reconstruction have to be obtained by STM. The other samples are grown on intrinsic GaAs exhibiting a resistance too high to be imaged by STM, so the measurements are normally performed by AFM. Many samples, with different InAs coverages and growth modes have been prepared and measured. The size and distribution of the dots obtained in various growth conditions have been measured. Two main growth modes have been analysed: Continuous (the In flux was never interrupted) and Migration Enhanced (the In flux was interrupted at regular intervals, in order to increase the atomic movements ad aggregation on the surface). The island size increases in the Migration Enhanced mode. The onset of the quantum dot formation has been evidenced by also by STM, by imaging 2D islands after which act as precursors. The results have been published in two papers [7-8]
Fig 3. STM images at 1.3 ML of InAs on GaAs(001); a) 2D-islands of average height 0.4 nm (precursors); b) high resolution image of the wetting layer. The RHEED image has been acquired in the MBE system at the end of the growth.
Fig 4. Needle-Sensor AFM of self-assembled quantum dots of InAs on GaAs(001) imaged using the VT SPM; dimensions: 300×300 nm. Height: 10 nm. The typical dot size is around 25 nm, and the height is 7 nm.
References on Ge/Si
[1] F. Boscherini, G. Capellini, L. Di Gaspare, F. Rosei, N. Motta and S. Mobilio, “Ge-Si intermixing in Ge quantum dots on Si(001) and Si(111)”, Appl. Phys. Lett. 76, 682 (2000).[2] F. Rosei, N. Motta, A. Sgarlata, G. Capellini and F. Boscherini, “Formation of the Wetting Layer in Ge/Si(111) studied by STM and XAFS”, Thin Solid Films 369 p29 (2000).[3] F. Boscherini, G. Capellini, L. Di Gaspare, F. Rosei, N. Motta and S. Mobilio, “Atomic intermixing in Ge Quantum Dots”,“ESRF Highlights” 1999, Surfaces and Interfaces (may be visualized on the web site www.esrf.fr).[4] F. Boscherini, G. Capellini, L. Di Gaspare, M. De Seta, F. Rosei, N. Motta A. Sgarlata and S. Mobilio, “Ge-Si intermixing in Ge quantum dots on Si”, Thin Solid Films 380, 173 (2000).[5] A. Sgarlata, F. Rosei, M. Fanfoni, N. Motta and A. Balzarotti, “STM/AFM study of Ge Quantum Dots grown on Si(111)”, IEEE Proceedings of the 11th International Semiconducting and Insulating Materials Conference, February 2000.[6] F. Rosei, N. Motta, A. Sgarlata and A. Balzarotti, “Growth and characterization of Ge nanostructures on Si(111)”, submitted for publication to Lecture Notes in Physics. (February 2001).[7] Nunzio Motta Self-assembled Quantum Dots studied by scanning probes and other structural techniques. Proc. Workshop on Nanotubes and Nanostructures 2000, S.M.Pula (CA), Ed. S.Bellucci, (Editrice Compositori 2001)[8] N. Motta, F. Rosei, A. Sgarlata, G. Capellini, S. Mobilio, F. Boscherini, Evolution of the intermixing process in Ge/Si(111) Self-assembled islands, submitted to Materials Science B
References on InAs/GaAs
[1] F. Patella, M. Fanfoni, F. Arciprete, S. Nufris, E. Placidi, and A. Balzarotti; Kinetic aspects of the morphology of self-assembled InAs quantum dots on GaAs(001) Applied Physics Letters 76 (2001) 320.[2] Arciprete, A. Balzarotti, M. Fanfoni, N. Motta, F. Patella, A. Sgarlata; Morphology of self-assembled quantum dots of InAs on GaAs(001) and Ge on Si(111) in Recent Research developments in Vacuum Science & Technology. Publisher: Transworld Research Network (2001).
Molecular Beam Epitaxy & Electron Spectroscopy
Molecular Beam Epitaxy
Characteristics
(Mod.32; Riber)Stainless steel UHV system (Standard pressure 6 10-11 mbar). Turbo molecular pump for roughing: 240 l/sec - Ionic pump: 500 l/sec - Titanium sublimator. X-Y-Z manipulator with resistive heating.
Tmax=800 °C. Knudsen cells: Ga, As, In, Al, Si (as dopant). Rheed optics E= 10 KeV.
High Resolution Electron Energy Loss Spectroscopy
HREELS cross section
Characteristics
Stainless steel UHV system (Standard pressure 4×10-11mbar). Turbo molecular pump for roughing: 240 l/sec - Ionic pump: 200 l/sec - Titanium sublimator. X-Y-Z manipulator with resistive heating. T max=800 °C. Leed optics.
Prof. Carla Andreani
Contact details
Office: Physics Department
Tel: +39 06 72594441
Lab: +39 06 72594422
Fax: +39 06 2023507
CA is Professor of Condensed Matter at the Faculty of Science of the University of Rome Tor Vergata.
Research Activity
Study of structure and dynamics of simple and complex fluids using spectroscopic techniques, (mainly x-ray and neutron scattering) and the design and construction of instrumentation for neutron scattering. CA most recent studies are about the static and dynamical properties of molecular (hydrogen bonded) and quantum systems in bulk and confined geometry [1,2,3,4]. Examples includes diatomic fluids, hydrogen halides, H2O, H2, D2, 3He, 4He and 3He/4He mixtures. Neutron scattering represents an important tool for the study of the properties of matter at the nanoscale, the ideal reciprocal space probe of microscopic correlations in bulk sample. Its provides relevant information to nanoscience and application to nanotechnology, which add and complement real space visualization and manipulation of matter on the nanometer scale. CA has been directly involved in the design and development of novel instrumentation for neutron spectroscopy at the eV energy, in particular DINS (Deep Inelastic neutron Scattering) [4,5]. The latter is the unique technique to access microscopic information on the dynamics and the local environment of light atoms and molecules in a variety of environments. Much of her work has focussed on the study of the single particle momentum distribution, n(p), and mean kinetic energy, K>, in light atoms and molecules, physical quantities which can be directly measured using DINS. In this area CA most recent work has been addressed to the study of liquid 3He and 4He and 3He - 4He mixtures [6], where the interplay between Bose and Fermi statistics dominates the behaviour, and to the study of liquid water in bulk and confined in nanopores. A recent research with eV spectroscopy is in progress where neutrons with energies similar to chemical bonds are used to produce quantitative measures and even 3D images of the elemental composition and physical structure of artefacts. This idea, aiming to develop an analysis technique based on neutron absorption, is quite innovative in the field of archaeology, with a number of scientific and technical challenges. This is the objective of the ANCIENT CHARM project
Teaching Activities
Undergraduate: Physics I and II (Biotechnology Degree)
Graduate: Spectroscopy (Degree in Physics)
PhD Schools: Experimental Techniques in Material Science (School Nanostructure and Nanotechnology, and School in Physics).
Administrative Responsabilities
Member of the Neutron Committee of Consiglio Nazionale delle Ricerche (CNR).
Member of the Administrative Board of University of Rome Tor Vergata.
Member of the ISIS Spallation Neutron Source Facility Access Panel (FAP) (2005-2007).
Member of the International Advisory Board of the Hungarian-Spanish ESS Collaboration.
Member of the Teaching Supervising Committee of the International Ph.D. Programs in Nanostructure and Nanotechnology, (a Joint Ph.D. Program between The Universities of Rome Tor Vergata and Milano Bicocca), and Physics (University Roma Tor Vergata).
Membership of Professional Bodies
Member of Italian Physical Society and American Chemical Society.
Editorial Roles
Editor of Notiziario Neutroni e Luce di Sincrotrone a journal supported by Consiglio Nazionale delle Ricerche (CNR)
Recent Publications
[1] A. Pietropaolo, R. Senesi, and C. Andreani, A. Botti, M. A. Ricci, and F. Bruni, Phys. Rev. Letts., 100, 127802 (2008)
[2] C. Pantalei, A. Pietropaolo, R. Senesi, S. Imberti, C. Andreani, J. Mayers, C. Burnham, and G. Reiter, Phys. Rev. Letts., 100, 177801 (2008).
[3] C. Andreani, C. Pantalei and R. Senesi, Journal of Physics Condensed Matter, 18, 5587 (2006)
[4] C. Andreani, D. Colognesi, J. Mayers, G. Reiter, R. Senesi, Advances in Physics, 54, 377 (2005)
[5] C. Andreani et al., Appl. Physics Letters, 85, 5454, (2004)
[6] R. Senesi, C. Andreani, D. Colognesi, A. Cunsolo, M. Nardone, Phys. Rev. Letts. 86, 4584, (2001)
Notes. CA is author of about 130 papers on international journals and about 100 scientific oral contributions at international conferences, meetings and schools.
Late News 3
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Late News 2
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Joint Laboratory for Advanced Nanostructured Materials for Energy, Catalysis and Biomedical Applications
Sub-Femtoseconds proton dynamics in confined geometry and near proteins
Collaborative research among scientists from Italy - the Nast Centre for Nanoscience Nanotechnology and Innovative Instrumentation, UK - ISIS Spallation Neutron Source - and US, - University of Huston - have used Deep Inelastic Neutron Scattering (DINS) to shows how the proton momentum distribution in liquid water monitors the changing occurring …