The temperature dependence of the elastic compliances of some alkali halides

The elastic moduli of LiF, NaF, NaCl and KCl single crystals have been measured in the temperature range 20-700°C by an audio frequency resonance method. The moduli were determined from the resonances of flexural and torsional modes of vibration of long thin rods and a knowledge of the room temperature moduli values which had been obtained previously. The elastic compliances s 11 , - s 12 and s 44 all increase with increasing temperature, typically by a factor of two in the range considered. Values extrapolated to 0°K are given, and the Debye temperatures are calculated from these.