Thermal expansion and temperature dependence of lattice vibration frequencies of caesium iodide and potassium iodide

Abstract

The linear thermal expansivity of KI and CsI single crystals have been measured from 300 to 670K by an interferometric method. The apparatus is outlined and expansivity values as a function of temperature are shown graphically together with those of previous workers. Values of the Gruneisen parameter gamma , determined previously by other workers, together with the present thermal expansivity values have been used to determine the temperature dependence of the lattice vibration frequencies.