Low Temperature Physics: 33, 573 (2007); https://doi.org/10.1063/1.2755181 (5 pages)
Физика Низких Температур: Том 33, Выпуск 6-7 (Июнь 2007), c. 752-757    ( к оглавлению , назад )

Lattice dynamics of cryocrystals at high pressure

E.E. Horbenko1,2, E.P. Troitskaya1, and Val.V. Chabanenko1

1Donetsk A.A. Galkin Institute of Physics and Technology of the National Academy of Sciences of Ukraine, 72 R. Luxemburg Str., Donetsk 83114, Ukraine

2Luhansk Taras Shevchenko National Pedagogical University, 2 Oboronna Str., Luhansk 91011, Ukraine
E-mail: e_g81@mail.ru

Received October 20, 2006


The lattice dynamics of cryocrystals is investigated from first principles in the framework of the Tolpygo model over a wide range of pressures. The phonon frequencies in rare-gas solids are calculated in terms of models that go beyond the scope of adiabatic approximation. At high pressure the phonon spectrum along the D and ∑ directions is distorted and the longitudinal L- and transverse T2-modes soften as a result of the electron–phonon interaction, with the relative contribution decreasing in the sequence Ar, Kr, Xe. The calculated phonon frequencies are in good agreement with the experimental data for argon crystals of a pressure 3.1 GPa.

63.20.Dj Phonon states and bands, normal modes, and phonon dispersion;
PACS: 63.20.Kr Phonon–electron and phonon–phonon interactions.

Ключевые слова: rare-gas solids, phonon spectrum, electron–phonon interaction, high pressure.