Calorimetric, Optical, and Anti-Phase Domain Studies on the Ferroelectric-Ferroelastic Ni_3B_7O_(13)Cl Boracite

摘要

The isobaric molar heat capacity of Ni_3B_7O_(13)C1 boracite at the ferroelectric 43m-mm2 phase transition is reported. Spontaneous birefringence measurements on single crystals of this composition from room temperature up to the transition temperature are also reported. It is shown by detailed analysis that antiphase domains are not to be expected in the cubic phase.