大型放射光施設 SPring-8

Speaker: Dr. Paul Dumas

Language: English

Affiliation: Synchrotron SOLEIL, France

Title: Multidisciplinary specificities of synchrotron infrared beamlines: from Material Science to Biology and Biomedicine.

Abstract:
Synchrotron Infrared spectroscopy and microscopy have significantly contributed to the recognition of such analytical approach in many scientific disciplines, not only on research field familiar with such vibrational technique, but also in unfamiliar communities such as biology. With the additional far infrared availability ( THz has being the first identified application at early days) , the coupling with microscopy, has tremendously motivated diverse communities and applications over the last 15 years.
This talk is related to some of highlighted applications in materials sciences ( high pressure, magneto resistance) , in biology and related medical applications carried out at the French infrared beamline, at SOLEIL synchrotron facility.
Very High pressure physics ( > 200 Gpa) exhibits unexpected formation of new structures and new compounds. Synchrotron Infrared spectroscopy is of paramount importance in such studies, since the sample size inside gaskets are often in the 10-20 microns range. A growing demand of infrared micro-spectroscopy (and imaging) for larger volume sample has emerged ( > 40 mm working distance)more particularly for High Pressure measurements in Diamond Anvil Cell. These requirements originated from the fact that less space constraints are needed for accommodating heating devices, cells of larger dimension ( and compatible with those used for X-rays diffraction and absorption). A dedicated horizontal microscope have been developed for coupling with the synchrotron beam, with large working distance Schwarzschilds ( > 42 mm), while keeping a large numerical aperture ( N.A.=0.5). In addition, the home built microscope is able to be operated in transmission or reflection modes, and “ in situ” fluorescence and Raman spectroscopy have been added.
This will be illustrated in the case of superionicity of NH3, and in the various phase formation of hydrogen and deuterium and some of their hydrides (Ref 1-3).
Magnetorefractive infrared microspectroscopy has been demonstrated in resolving spatial variations in Giant MagnetoResistance (GMR). Using modeling, an insight into the origin of the variations in a CoFe/Cu multilayer has been obtained (local variations in interlayer coupling locally changing the switching field). The observed spatial variations have been shown to be masked in conventional four-probe electrical measurements.( Ref 4)
Synchrotron infrared spectroscopy and micro-spectroscopy held a big promise in medical diagnosis. powerful methology to identify metabolic changes occurring at single cell level. Among several examples, the talk will focus on the following:
•Urinary stone disease
•Human leukemia cells and their resistance to drug treatment.
• Stem cells research
•Liver steatosis : how a database established with the synchrotron source is actually used to condition an IR thermal source based microscope, to be set up in hospital for direct diagnostic during liver transplant.

( 1)- Liu, C., Mafety, A., Queyroux, J.A., Wilson, C.W., Zhang, H., Béneut, K., Le Marchand, G., Baptiste, B., Dumas, P., Garbarino, G., Finocchi, F., Loveday, J.S., Pietrucci, F., Saitta, A.M., Datchi, F., Ninet, S. "Topologically frustrated ionisation in a water-ammonia ice mixture" Nature Communications., 8: art.n° 1065. (2017).

(2)-Loubeyre, P., Occelli, F., Dumas, P. "Hydrogen phase IV revisited via synchrotron infrared measurements in H2 and D2 up to 290 GPa at 296 K" Physical Review B., 87(13): art.n° 134101. (2013).

(3)-Pepin, C., Loubeyre, P., Occelli, F., Dumas, P. "Synthesis of lithium polyhydrides above 130 GPa at 300 K" PNAS., 112(25): 7673–7676. (2015).

(4)-Kelley, C.S., Thompson, S.M., Gilks, D., Sizeland, J., Lari, L., Lazarov, V.K., Matsuzaki, K., LeFrançois, S., Cinque, G., Dumas, P. "Spatially Resolved Variations in Reflectivity Across Iron Oxide Thin Films" Journal of Magnetism and Magnetic Materials., 441: 743-749. (2017).

担当者: 池本夕佳
e-mail: ikemotospring8.or.jp
PHS: 3450