Thermodynamics and microstructure of vacancies in rare gas crystals at high temperature
A.I. Karasevskii and V.V. Lubashenko
G.V. Kurdyumov Institute for Metal Physics, 36 Vernadsky Str., Kiev 03142, Ukraine
Received September 7, 2006
A self-consistent statistical method is used to calculate the Gibbs free energy of vacancy formation in heavy rare gas crystals at high temperature. It is shown that the vacancy formation free energy rapidly falls in the vicinity of the melting point of the crystal. Such behavior is attributed to approaching the anharmonic
instability point of vibrational subsystem of the solid.
PACS: 61.72.Bb Theories and models of crystal defects; PACS: 61.72.Ji Point defects (vacancies, interstitials, color centers, etc.) and defect clusters; PACS: 64.70.Dv Solid-liquid transitions.
Key words: vacancy formation, rare gas crystals.