Velocity of Sound in Superconducting Tin

Abstract
The ultrasonic pulse method has been used to measure the velocity of 10-Mc/sec sound waves in poly-crystalline tin from 295°K to 2°K. The superconducting state has no effect (±0.3 percent) on the velocity and attenuation of longitudinal and of transverse waves. The value of θD computed from these velocity measurements at the very low temperature is 210°K.