The ultrasonic pulse technique has been used in conjunction with a specially devised cryogenic technique to measure the velocities of 10-Mc/sec acoustic waves in copper single crystals in the range from 4.2°K to 300°K. The ...

The composite piezoelectric oscillator is employed to measure the adiabatic elastic moduli of crystalline aluminum over the temperature interval 63'K to 773 K. The data permit a valid extrapolation to O'K. The Debye ...