On critical thresholds in the response of silicates under shock

This paper investigates behaviours observed when the strength of a material’s atomic structure is breached, considering silicates and their response under compression in the regime up to ca. 130 GPa. It focuses on analysis of shock data and proposes that exceeding the threshold at which the theoretical strength is overcome, the weak shock limit (WSL), leads to a range of observed new mechanisms. In crystalline quartz, this indicates an end to weak shock behaviour beyond 40 GPa, regardless of orientation. This threshold is shown to apply to amorphous materials as well. A second threshold is seen at higher pressures that correlates with the end of strong shock behaviour. These two thresholds correspond to a transition in electronic and magnetic properties that define behaviour in material states above these thresholds.