Monitoring high-temperature solid–solid phase transitions of HMX with atomic force microscopy

Using high-temperature atomic force microscopy we have observed the solid–solid phase transition of octahydro-1,3,5,7,-tetrazocine (HMX) in real time. Massive surface reconstruction occurs during the first-order transition. The temperature induced increase in void space and surface roughness observed in the δ polymorph of HMX serve to increase the growth rate and volume of shock initiated hot spots and hence reaction sensitivity.