Pyridinium salt investigations under high pressure: pressure-induced phase transitions in ferroelectric pyridinium perrhenate

Abstract

The properties of pyridinium perrhenate have been studied by three methods: dielectric spectroscopy, neutron powder diffractometry and NMR spectrometry under high pressure. It has been shown that under high pressure the temperatures of the two phase transitions in the crystal are shifted towards lower ones. Moreover, the results have shown the occurrence of a new high pressure phase with a triple point corresponding to the pressure of 100 MPa and the temperature of 240 K.