Abstract
TheE g andT 2g acoustic phonon modes of the molecular crystals KBr0.96(CN)0.04 and KBr0.86(CN)0.14 have been investigated by inelastic neutron scattering at 6, 90 and 300 K. Clear resonances due to mode-mode coupling to molecular excitations were observed. In complementary ultrasonic experiments the elastic constants were found to pass through minima as a function of temperature. The results were quantitavely explained by a model which assumes simple forms of the molecular excitation spectrum. An alternative interpretation, though being only qualitative, postulates a freezing of the CN molecules into a glass-like phase.
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Research supported by the BMFT, W.-Germany
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Loidl, A., Feile, R., Knorr, K. et al. Coupled rotational and translational modes in the mixed molecular crystal KBr1−x (CN) x . Z. Physik B - Condensed Matter 38, 253–262 (1980). https://doi.org/10.1007/BF01315664
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DOI: https://doi.org/10.1007/BF01315664