Pentaerythritol tetranitrate (PETN) powders are used to initiate other explosives. During long-term storage, changes in powder
properties can cause changes in the initiation performance. Changes in the morphology and surface area of aging powders are
observed due to sublimation and growth of PETN crystals through coarsening mechanisms, (e.g. Ostwald ripening, sintering,
etc.). In order to alleviate the sublimation of PETN crystals under service conditions, stabilization methods such as thermal
cycling and doping with certain impurities during or after the crystallization of PETN have been proposed.
In this report we present our work on the effect of impurities on the morphology and activation energy of the PETN crystals.
The pure and impurity doped crystals of PETN were grown from supersaturated acetone solution by solvent evaporation technique
at room temperature. The difference in the morphology of the impurity-doped PETN crystal compared to pure crystal was examined
by optical microscopy. The changes in the activation energies and the evaporation rates are determined by thermogravimetry
(TG). Our activation energies of evaporation agree with earlier reported enthalpies of vaporization. The morphology and activation
energy of PETN crystals doped with Ca, Na, and Fe cations are similar to that for pure PETN crystal, whereas the Zn-ion-doped
PETN crystals have different morphology and decreased activation energy.