Switchable crystal–amorphous states of NiSO4·6H2O induced by a Reddy tube

Abstract

Dynamic supersonic shock waves have a very fascinating property of inducing phase transitions in materials, as is evident from the present research work. Despite much experimental and theoretical research work that has been carried out over the past 100 years on shock waves, which has brought about significant contributions to understanding the irreversible phase transition behaviour of materials under shocked conditions, the concept of switchable phase transitions, especially from the crystalline to amorphous as a result of dynamic shock waves, is not clearly understood. In the present framework, the authors reveal and present the novel results of a switchable phase transition occurring between the crystalline (C) and amorphous (A) phases in a nickel sulfate hexahydrate single-crystal triggered by dynamic shock waves under ambient conditions, thereby following the sequence of C–C–A–C–A–C–A–C–A when the number of shock pulses is 0, 1, 2, 3, 4, 5, 6, 7, and 8, respectively. The observed results of the phase transition are convincingly reflected through diffraction, spectroscopic, and microscopic analyses.