Static compressibility of V3Si to 20 kbar

The static compressibilities of V3Si and V or Cu at room temperature have been measured simultaneously using strain-gauge techniques in a fluid medium to pressures ∼ 20 kbar. Although V and Cu behaved in a normal manner, the data for V3Si were found to be sample and pressure history dependent, failed to follow the ultrasonic prediction, and generally exhibited nonlinearities with pressure. The results support the earlier finding of an anomalous compressibility by Blaugher, Taylor, and Ashkin, and indicate a new physical process for mechanical compliance with a time scale > 10-7 sec. It is concluded that hydrostatic pressure may lead to changes of a structural or defect nature in addition to the expected lattice-parameter reduction.