High pressure studies of potassium perchlorate

Two experiments are reported on KClO4 at extreme conditions. A static high pressure Raman study was first conducted to 18.9 GPa. Evidence for at least two new phases was observed: one between 2.4 and 7.7 GPa (possibly sluggish), and the second near 11.7 GPa. Then, the X-ray induced decomposition rate of potassium perchlorate (KClO4 ->(hv) KCl + 2O(2)) was studied up to 15.2 GPa. The time-dependent growth of KCl and O-2 was monitored. The decomposition rate slowed at higher pressures. We present the first direct evidence for O-2 crystallization at higher pressures, demonstrating that O-2 molecules aggregate at high pressure. (C) 2016 Elsevier B.V. All rights reserved.