Structural Phase Transition Peculiarities in Ion-Molecular Perchlorate Crystals

Abstract

Molecular relaxation processes are inspected in potassium and cesium perchlorates (KClO4 and CsClO4, respectively) via Raman spectroscopy. A first-order phase transition in KClO4 and CsClO4 crystal perchlorates is found to be extended. A pretransition region is also detected in KClO4 and CsClO4 systems, wherein the vibrational band widths are shown to remain almost unchanged, but abruptly increase at the phase transition point.