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Scientific Report 2007-2009<br />
Laboratories and Facilities of the Department of Physics<br />
L5. Infrared Spectroscopy Lab<br />
The Infrared Spectroscopy (IRS) laboratory is working in the<br />
<strong>Sapienza</strong> Dept. of Physics since the end of the 1960’s, when the<br />
first Fourier-transform Michelson interferometers appeared on the<br />
market. It was established by late Professor Salvatore Cunsolo,<br />
who had collaborated with Professor H. P. Gush to the development<br />
of one of such devices, during a sabbatical year at the<br />
University of British Columbia (Canada). That instrument after<br />
became the prototype of a performant series of interferometers<br />
produced by Bomem, a spin-off of British Columbia.<br />
Today, the IRS laboratory (permanent staff P. Calvani, S.<br />
Lupi, P. Maselli and A. Nucara) is focused on the spectroscopy<br />
of solids characterized by strong electron-electron correlation<br />
and/or electron-phonon interaction. Among them, there are<br />
novel superconductors like the high-T c cuprates , the FeAs compounds,<br />
and metallic diamond. Also the colossal-resistance manganites,<br />
the vanadium oxides, the charge-ordered systems and the<br />
multiferroics have been widely investigated in the last years in a<br />
Figure 1: The Bruker 66V interferometer equipped with<br />
a liquid helium cryostat and with an infrared microscope.<br />
wide range of temperature and pressures. In those systems infrared spectroscopy, with its high spectral resolution and low<br />
perturbation, allows one to identify the low-energy excitations which are relevant to the electrodynamics of the solid, and<br />
to its phase transitions. Finally, an increasing activity is in progress in the domain of biophyisics. Immobilized enzymes<br />
(Lipase) on nanostructured polymers are being studied by Infrared spectroscopy, to understand the enhancement of their<br />
activity in such conditions. Another investigation concerns the study of proteins presnt in food, to find imprints of their<br />
different bio-availability by the human metabolism is related to easily identifiable spectral features.<br />
The IRS Lab also routinely performs tests on infrared windows, filters, sources and detectors, as well as simulations and<br />
calculations, aimed at the development of new infrared sources, especially those synchrotron-based and the Fee-Electron<br />
Lasers (FEL). Presently the IRS group, in addition to the laboratory at the Dept. of Physics in Rome, manages an<br />
experimental station on the infrared beamline SISSI at ELETTRA (Trieste) and another one on the beamline SINBAD<br />
at DAFNE (Frascati). Moreover, the group collaborates to the exploitation of Terahertz coherent radiation from the FEL<br />
SPARC (Frascati). In this context, new activities started recently at the IRS Lab, concerning the applications of the<br />
metamaterials and of nanostructured materials - like Quantum Wells - to THz spectroscopy.<br />
The IRS laboratory in Rome is instead devoted to spectroscopy<br />
with conventional black-body sources. Therein, we can perform<br />
virtually any kind of infrared/visible spectrum (transmittance,<br />
reflectance, diffuse reflectance, Attenuated Total Reflectance, Infrared<br />
Microspectroscopy) from the sub-Terahertz range to the<br />
Ultraviolet. To this aim, one can use two Michelson interferometers<br />
(a Bomem DA3 and a Bruker 66 V, shown in Fig. 1) coupled<br />
to nitrogen- and helium-cooled detectors, or a monochromator<br />
coupled to a CCD camera. These instruments are equipped<br />
with cryogenics for taking spectra down to 10 K, and with an<br />
optical oven which can heat the samples up to 550 K. The laboratory<br />
is also equipped with diamond anvil cells for collecting<br />
infrared spectra up to 20 GPa (200 Kbar) and with the necessary<br />
high-pressure technology. Finally, a small chemical laboratory<br />
is present for the treatment of solid samples and powders. It includes<br />
a system for polishing and washing the crystals, an oven, a<br />
diamond-wire saw for cutting the crystals, microscopes and other<br />
minor instrumentation.<br />
Figure 2: The remotely controlled set-up for highprecision<br />
reflectance measurements on small single crystals,<br />
mounted in the sample chamber of the Bomem DA3<br />
interferometer.<br />
http://www.phys.uniroma1.it/gr/irs/<br />
Related research activities: C6, C46.<br />
<strong>Sapienza</strong> Università di Roma 179 Dipartimento di Fisica