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Raman scattering in osmium under pressure

Yu. S. Ponosov·I. Loa·V. E. Mogilenskikh·K. Syassen
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Abstract

The effect of pressure and temperature on the Raman-active phonon mode of osmium metal has been investigated for pressures up to 20 GPa and temperatures in the range 10--300 K. Under hydrostatic conditions (He pressure medium) the phonon frequency increases at a rate of 0.73(5) cm^{-1}/GPa (T = 300 K). A large temperature-induced and wavelength-dependent frequency shift of the phonon frequency is observed, of which only a small fraction can be associated with the thermal volume change. The main contribution to the temperature dependence of the phonon frequency is rather attributed to non-adiabatic effects in the electron-phonon interaction, which explains also the observation of an increasing phonon line width upon cooling. The phonon line width and the pressure-induced frequency shift were found to be unusually sensitive to shear stress.

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Yu. S. Ponosov, I. Loa, V. E. Mogilenskikh, K. Syassen. 2005-03-11. Raman scattering in osmium under pressure. https://doi.org/10.1103/physrevb.71.220301

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