The speed of sound in solidified inert gases
Аннотация
The pulse method is used to measure the velocity of longitudinal and transverse ultrasound waves at a frequency of 1 MHz in crystals of neon (2–20°K), krypton (20–110°K), and xenon (40–150°K). The data obtained are used to determine adiabatic and isothermal elastic characteristics of the solidified inert gases, their Debye temperatures, and Griineisen coefficients. Comparison of the values found with calculated results allows evaluation of the suitability of various theoretical models for description of lattice dynamics in these crystals. Temperature dependences of sound speeds in reduced variables in the crystals studied were compared. It is shown that the temperature behavior of sound speeds obeys the law of corresponding states, with the deviations appearing in the cases of argon and neon being a manifestation of quantum effects connected with atomic zero point oscillations.