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1. Micro-beam and pulsed laser beam techniques for the micro-fabrication of diamond surface and bulk structures

Author

Sciortino, S., Bellini, M., Bosia, F., Calusi, S., Corsi, C., Czelusniak, C., Gelli, N., Giuntini, L., Gorelli, F., Lagomarsino, S., Mando, P. A., Massi, M., Olivero, P., Parrini, G., Santoro, M., Sordini, A., Sytchkova, A., Taccetti, F., and Vannoni, M.

Subjects
Condensed Matter - Materials Science
Abstract

Micro-fabrication in diamond is involved in a wide set of emerging technologies, exploiting the exceptional characteristics of diamond for application in bio-physics, photonics, radiation detection. Micro ion-beam irradiation and pulsed laser irradiation are complementary techniques, which permit the implementation of complex geometries, by modification and functionalization of surface and/or bulk material, modifying the optical, electrical and mechanical characteristics of the material. In this article we summarize the work done in Florence (Italy) concerning ion beam and pulsed laser beam micro-fabrication in diamond., Comment: 14 pages, 5 figures

Published
2016
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2. Pressure-tuning of the electron-phonon coupling: the insulator to metal transition in manganites

Author

Postorino, P., Congeduti, A., Dore, P., Gorelli, F. A., Ulivi, L., Sacchetti, A., Kumar, A., and Sarma, D. D.

Subjects
Condensed Matter - Materials Science
Abstract

A comprehensive understanding of the physical origin of the unique magnetic and transport properties of A_(1-x)A'^xMnO_3 manganites (A = trivalent rare-earth and A' = divalent alkali-earth metal) is still far from being achieved. The complexity of these systems arises from the interplay among several competing interactions of comparable strength. Recently the electron-phonon coupling, triggered by a Jahn-Teller distortion of the MnO_6 octahedra, has been recognised to play an essential role in the insulator to metal transition and in the closely related colossal magneto-resistance. The pressure tuning of the octahedral distortion gives a unique possibility to separate the basic interactions and, at least in principle, to follow the progressive transformation of a manganite from an intermediate towards a weak electron-phonon coupling regime. Using a diamond anvil cell, temperature and pressure-dependent infrared absorption spectra of La_(0.75)Ca_(0.25)MnO_3 have been collected and, from the spectral weight analysis, the pressure dependence of the insulator to metal transition temperature T_IM has been determined for the first time up to 11.2 GPa. The T_IM(P) curve we proposed to model the present data revealed a universality character in accounting for the whole class of intermediate coupling compounds. This property can be exploited to distinguish the intermediate from the weak coupling compounds pointing out the fundamental differences between the two coupling regimes., Comment: 8 pages, 4 figures

Published
2003
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8. Local structure of solid Rb at megabar pressures.

Author

De Panfilis, S., Gorelli, F., Santoro, M., Ulivi, L., Gregoryanz, E., Irifune, T., Shinmei, T., Kantor, I., Mathon, O., and Pascarelli, S.

Subjects
*MOLECULAR structure, *HIGH pressure (Technology), *X-ray absorption, *CHEMICAL stability, *SINGLE crystals
Abstract

We have investigated the local and electronic structure of solid rubidium by means of x-ray absorption spectroscopy up to 101.0 GPa, thus doubling the maximum investigated experimental pressure. This study confirms the predicted stability of phase VI and was completed by the combination of two pivotal instrumental solutions. On one side, we made use of nanocrystalline diamond anvils, which, contrary to the more commonly used single crystal diamond anvils, do not generate sharp Bragg peaks (glitches) at specific energies that spoil the weak fine structure oscillations in the x-ray absorption cross section. Second, we exploited the performance of a state-of-the-art x-ray focussing device yielding a beam spot size of 5 × 5 μm², spatially stable over the entire energy scan. An advanced data analysis protocol was implemented to extract the pressure dependence of the structural parameters in phase VI of solid Rb from 51.2 GPa up to the highest pressure. A continuous reduction of the nearest neighbour distances was observed, reaching about 6% over the probed pressure range. We also discuss a phenomenological model based on the Einstein approximation to describe the pressure behaviour of the mean-square relative displacement. Within this simplified scheme, we estimate the Grüneisen parameter for this high pressure Rb phase to be in the 1.3-1.5 interval. [ABSTRACT FROM AUTHOR]

Published
2015
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11. Rayons-X pour la caractérisation des nanocomposites inorganiques-organiques

Author

van Der Lee, Arie, Thibaud, J.-M., Hermet, P., Cambon, O., Renzo, F. Di, Rouquette, J., Ceppatelli, M., Scelta, D., Dziubek, K., Gorelli, F., Bini, R., Santoro, M., Haines, J., Institut Européen des membranes (IEM), Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM), and Herrada, Anthony

Subjects
[CHIM] Chemical Sciences, [CHIM]Chemical Sciences, ComputingMilieux_MISCELLANEOUS
Abstract

National audience

Published
2015

12. Use of Fourier Maps to Study High Pressure Guest Insertion and Polymerization in Zeolites

Author

Haines J., Thibaud J. M., Alabarse F., Rouquette J., Hermet P., Cambon O., Coasne B., Di Renzo F., Van der Lee A., Scelta D., Ceppatelli M., Dziubek K., Gorelli F., Bini R., and Santoro M.

Subjects
Zeolites, Fourier Maps, Polymerization
Abstract

Zeolites represent an important family of porous materials based on corner sharing TO4 (T=Al, Si,...) tetrahedra. The microporous nature of these materials allows insertion of a great variety of guest atoms, ions or molecules giving rise to a large number of technological applications in catalysis, molecular sieves and ion-exchange materials. High pressure can be used to completely fill the subnanometric pores with guest molecules, thereby strongly modifying the mechanical, electrical and optical properties of the host zeolite. In the case of simple organic molecules, polymerization can be induced under high pressure eventually with the aid of UV irradiation to produce novel nanocomposite materials, which can be recovered at ambient pressure. Insertion of guest molecules (H2O, CO, CO2, C2H2, C2H4, Ar) in different hydrophilic and hydrophobic AlPO4 and SiO2 zeolite-type materials was studied by single crystal and powder x-ray diffraction using both synchrotron and laboratory sources [1-4]. The guest molecules present significant disorder and Fourier maps provide important information on the distribution of guests in the pores. In the case of zeolite/polymer nanocomposites, Fourier maps can be used to characterize the translational, orientational and occupational disorder of the isolated polymer chains, which have a strong influence on the properties of the nanocomposite. 1. J. Haines, O. Cambon, C. Levelut, M. Santoro, F. Gorelli, G. Garbarino, J. Am. Chem. Soc. 2010, 132, 8860. 2. M. Santoro, F. A. Gorelli, R. Bini, J. Haines, and A. van der Lee, Nature Commun ., 2013, 4, 1557. 3. D. Scelta, M. Ceppatelli, M. Santoro, R. Bini, F. A. Gorelli, A. Perucchi, M. Mezouar, A. van der Lee, J. Haines, Chem. Mater., 2014 , 26, 2249. 4. F. G. Alabarse, J. Rouquette, B. Coasne, A. Haidoux, C. Paulmann, O. Cambon, J. Haines, J. Am. Chem. Soc., 2015, 137, 584.

Published
2015

16. Micro-beam and pulsed laser beam techniques for the micro-fabrication of diamond surface and bulk structures

Author

Sciortino, S., primary, Bellini, M., additional, Bosia, F., additional, Calusi, S., additional, Corsi, C., additional, Czelusniak, C., additional, Gelli, N., additional, Giuntini, L., additional, Gorelli, F., additional, Lagomarsino, S., additional, Mandò, P.A., additional, Massi, M., additional, Olivero, P., additional, Parrini, G., additional, Santoro, M., additional, Sordini, A., additional, Sytchkova, A., additional, Taccetti, F., additional, and Vannoni, M., additional

Published
2015
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19. New perspectives for the Silicon-On-Diamond material

Author

Lagomarsino, S., Parrini, G., Sciortino, S., Fossati, A., Citroni, M., Ferrari, G., Gorelli, F., Santoro, M., Molesini, G., Vannoni, M., Marras, A., Scorzoni, Andrea, Berdondini, L., Brandi, F., Carzino, R., Diaspro, A., Scotto, M., and Torre, B.

Published
2009

27. Lattice Dynamics of Dense Lithium

Author

Gorelli, F. A., primary, Elatresh, S. F., additional, Guillaume, C. L., additional, Marqués, M., additional, Ackland, G. J., additional, Santoro, M., additional, Bonev, S. A., additional, and Gregoryanz, E., additional

Published
2012
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31. Silicon-on-diamond material by pulsed laser technique

Author

Lagomarsino, S., primary, Parrini, G., additional, Sciortino, S., additional, Santoro, M., additional, Citroni, M., additional, Vannoni, M., additional, Fossati, A., additional, Gorelli, F., additional, Molesini, G., additional, and Scorzoni, A., additional

Published
2010
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50. Evidence of Phase Separation in the P-T Phase Diagram of the La0.75Ca0.25MnO3 Manganite by Infrared Measurements.

Author

Dore, P., Sacchetti, A., Postorino, P., Congeduti, A., Gorelli, F., and Ulivi, L.

Abstract

Recent infrared absorption measurements performed at different pressures and temperatures on the La0.75Ca0.25MnO3 manganite provided an estimate of the insulator-to-metal transition temperature T IM( P), i.e., the P- T phase diagram of a pseudocubic manganite. Here we consider in detail the P- and T-dependence of the absorption spectral weights n *. The n *( T, P) behavior gives evidence of phase-separation between conducting and insulating domains in the P-T phase diagram, and allows to establish the occurrence of a characteristic temperature T * ≅ 0.6 T IM. For T > T *, when insulating domains decrease on decreasing temperature or on increasing pressure, it is possible to distinguish a metallic region (connected metallic domains) for T * < T < T IM, and an insulating region (disconnected metallic domains) for T > T IM. Below T *, no reduction of the insulating domains, that may still exist, occurs. [ABSTRACT FROM AUTHOR]

Published
2005
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