The prediction that certain cubic metals may not be precisely cubic throughout a range of temperature below their melting points led to the present investigation. Pure copper was chosen as the cubic metal to examine for ...

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 ...