Piezoelectric Current from Shock-Loaded Quartz—A Submicrosecond Stress Gauge

Abstract

Current from X‐cut quartz disks may be used to detect stress‐time profiles induced by shock loading. The current amplitude and its time dependence are functions of the dielectric, piezoelectric, and mechanical properties of quartz under shock‐loading conditions. The results of an extensive experimental study of the current from shock‐loaded quartz disks are reported for shock stress up to 50 kbar. The experiment is performed by impacting precisely aligned X‐cut quartz disks upon each other at various measured velocities and observing the current in one of the disks during the first wave transit. Within the low signal range, the piezoelectric stress constant e₁₁ is found to be 0.174 C‐m⁻². The coefficient relating current jump to stress jump in one‐dimensional strain is found to be 2.04×10⁻⁸ C‐cm⁻²‐kbar⁻¹ up to 6 kbar and 2.15×10⁻⁸ C‐cm⁻²‐kbar⁻¹ from 9 to 18 kbar. The wave velocity was determined to be constant to 25 kbar. The observed current waveform could be fully interpreted in terms of rate‐independent properties. Determinations of distortions to the current from apparently minor deviations from one‐dimensional conditions were also made.