Phase Transitions in Bis(4-chlorophenyl)sulfone as Studied by 35Cl FT-NQR

Abstract

AbstractThe temperature dependence of 35Cl NQR frequencies in bis(4-chlorophenyl)sulfone was measured in the temperature range of 4.2-297 K. Below 115 K four NQR lines due to four inequivalent chlorines exist in the commensurate phase, contrary to the single NQR line reported by Corbero et al. It follows that the commensurate-incommensurate transition is of the first-order, and the incommensurate-normal transition at 150 K is quasi-continuous. It is also suggested that the successive phase transitions are triggered by the small angle rotation of the molecules about their C2-axes.