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 delta polymorph of HMX serve to increase the growth rate and volume of shock initiated hot spots and hence reaction sensitivity.