Ferroelasticity in ReP₅O₁₄ (Re : La-Tb)

Abstract

The ferroelasticity of rare earth pentaphosphates, ReP 5 O 14 (Re : La, Ce, Pr, Nd, Sm, Eu, Gd and Tb) which belongs to the species mmmF2/m is studied by DSC, Weissenberg camera and polarizing microscope. Anomaly of heat capacity at the ferroelastic transition point (second order), ferroelastic hysteresis loop, space group in para phase ( Pncm a =8.822, b =9.142, c =13.13 A at 150°C LaP 5 O 14 ), temperature dependence of ferroelastic order parameter and indicatrix are obtained.