MEASUREMENT OF THE ELASTIC-CONSTANTS OF POLYCRYSTALS BY THE RESONANCE METHOD IN A CYLINDRICAL SPECIMEN - (MEASUREMENT AT LIQUID HE TEMPERATURE)

The resonance method of three-dimensional free vibrations with the cylindrical specimen, which has been developed by the authors, was applied to determine the elastic constants of polycrystals in a temperature range of 4-300 K. It was found that the temperature dependence of elastic constants of pure aluminum agreed well with published data measured by the ultrasonic pulse-echo technique over the temperature range of measurements. A sluggish change induced could also be detected in niobium. In addition, the temperature dependence of elastic constants for superconducting Al-Si and Al-Ge supersaturated solid solutions was examined, and the Debye temperature was determined by extrapolating the elastic constants to the values at 0 K.