Low temperature thermal diffusivity of LiKSO4 obtained using the photoacoustic phase lag method

Abstract

This paper describes the determination of the thermal diffusivity of LiKSO4 crystals using the photoacoustic phase lag method, in the 77 K to 300 K temperature interval. This method is quite simple and fast and when it is coupled to a specially designed apparatus, that includes a resonant photoacoustic cell, allows for the determination of the thermal diffusivity at low temperatures. The thermal diffusivity is an important parameter that depends on the temperature, and no values of this parameter for LiKSO4, at low temperature, have yet been reported. The LiKSO4 is a crystal with many phase transitions which can be detected via the anomalies in the variation of the thermal diffusivity as a function of the temperature

Ferroelastic crystals and their nonlinear elastic properties observed in frequency range from gigahertz to milihertz

“…For the sample thickness h ¼ 0.27 cm and the thermal diffusivity constant D ¼ 10 À7 m 2 s À1 [54], the relaxation time calculated from Equation (20) is th ¼ 7.4 s. This means that the contribution of the thermal relaxation to the results of the DMA measurement can be excluded and adiabatic values of the storage modulus were measured.…”