Low Temperature Physics: 29, 711 (2003); https://doi.org/10.1063/1.1614174 (5 pages)
Физика Низких Температур: Том 29, Выпуск 9-10 (Сентябрь 2003), c. 951-956    ( к оглавлению , назад )

Influence of vibrational anharmonicity and vacancies on thermodynamic properties of the rare gas crystals

A.I. Karasevskii

Institute for Metal Physics of the National Academy of Science of Ukraine 36 Vernadsky Blvd., Kiev 03142, Ukraine
E-mail: akaras@imp.kiev.ua

W.B. Holzapfel

Department Physik, Universität Paderborn, D-33095 Paderborn, Germany

Аннотация

A statistical method is used to calculate thermodynamic properties of Ar, Kr and Xe (isobaric and isochoric heat capacity, bulk modulus, thermal expansion coefficient, interatomic distances, Grüneisen parameter), and good agreement with experimental values is observed. It is shown that at high temperature, slightly above the melting point of the rare gas crystals, an instability of the crystalline state occurs. As temperature approaches this instability the isobaric heat capacity and the thermal expansion coefficient show strong increases similar to the experimentally observed anomalies.

PACS:
63.70.+h - Statistical mechanics of lattice vibrations and displacive phase transitions
64.30.+t - Equations of state of specific substances
05.70.Ce - Thermodynamic functions and equations of state (see also 51.30.+i Thermodynamic properties, equations of state in physics of gases; for equations of state of specific substances, see 64.30.+t)