The Thermal and Ultrasonic Properties of Hot-pressed Cadmium Sulfide and Hot-pressed Magnesium Fluoride

Abstract
The thermal properties of certain pressed materials have been measured. In particular, specific heat measurements on hot-pressed and single crystal cadmium sulfide have been made between 1 and 20 K. An anomalous specific heat in the pressed material was observed below 1.5 K, and it is believed to be associated with the electronic structure of defects. The thermal conductivity of hot-pressed cadmium sulfide and hot-pressed magnesium fluoride has been measured in the temperature range 2 to 90 K. The results are compared with the single crystal data. The data are analyzed with a model that includes phononphonon interactions, pointdefect scattering, dislocation scattering, and boundary scattering. The sound velocity and ultra-sonic attenuation of hot-pressed CdS and hot-pressed MgF2 have been measured between 4 K and room temperature.