Effect of hydrostatic pressure on the ferroelastic phase transition in [N1-xPx(CH3)(4)](2)ZnBr4

Single crystals of the mixed compound [N1-xPx(CH3)(4)]2ZnBr4 were grown, and the effect of hydrostatic pressure on the ferroelastic phase transition has been studied by dielectric-constant measurements in a pressure range up to about 700 MPa. The transition temperature linearly increases with increasing pressure for whole range of x. The pressure coefficient of the transition temperature increases as x increases from 0.155 K/MPa for x = 0 to 0.224 K/MPa for x = 1. There is a positive correlation between the transition temperature and the its pressure coefficient. No pressure-induced intermediate phase has been observed between the normal and ferroelastic phases.