GaPO Single Crystals: Growth Condition by Hydrothermal Refluxing Method.

Bulk GaPO is an advanced piezoelectric material operating under high temperatures according to the α-β phase transition at 970 °C. This work presents the technological development of a hydrothermal refluxing method first applied for GaPO single crystal growth. Crystals of 10-20 g were grown in mixtures of aqueous solutions of low- and high-vapor-pressure acids (HPO/HCl) at 180-240 °C (10-20 bars).