Effect of Zn doping on the sublimation rate of pentaerythritol tetranitrate using atomic force microscopy.

A series of Zn ion-doped pentaerythritol tetranitrate (PETN) nanoislands in the form of thin films were prepared on Si substrates using spin coating. The effect of Zn concentrations on the sublimation energy was investigated by atomic force microscopy (AFM). The pure and Zn-doped nanoislands are imaged by AFM in contact mode at room temperature after annealing isothermally for a given time. The volume of the islands starts to decrease after annealing at 45 degrees C for pure PETN, whereas Zn-doped nanoislands start to decrease in height and volume after annealing at 55-58 degrees C. The minimum activation energy is found to be 29.7 Kcal/mol for 1,000 ppm Zn concentration. These studies are important for the long-term stabilization of PETN.