The mechanical reactivity of FOX-7: insights from high-pressure inelastic neutron spectroscopy

Energetic materials offer a fascinating class of mechanically reactive materials with import technological applications. Understanding how these materials react under mechanical impact is key to unlocking their full potential and designing better technologies. Using theoretical models we have recently demonstrated that mechanical reactivity follows from the interaction of a mechanical strain with the vibrational motions of the solid material. At the core of this phenomenon is the effect of mechanical strain on the lowest frequency lattice vibrations of the material. However, these vibrations are difficult to characterise using conventional spectroscopy, and our models have been therefore based on benchmarks from ambient pressure spectroscopy. Using a model energetic material (FOX-7) we will study how pressure affects the vibrational spectrum of a mechanically reactive solid using inelastic neutron scattering spectroscopy at TOSCA. Coupled with our simulations, these data will provide the first direct insights into how pressure can modify the low frequency vibrational spectrum of EMs and hence the essential role of mechanical strain on their mechanical reactivity.