Flux Growth and Characterizations of Ga₃PO₇ Single Crystals

Trigallium phosphate single crystals, Ga3PO7, have been grown for the first time by a spontaneous nucleation method using Li2CO3-3MoO3 as a flux. The crystal structure was determined by using a four circle X-ray diffractometer. The trigonal unit cell parameters are a = b = 7.897(3) Å, c = 6.757(6) Å, and Z = 3 with space group R3m. The crystal has a Mohs hardness of 6.5 and a density of 4.874 g/cm3 as determined by using Archimedes’ method. Analysis of differential scanning calorimetry (DSC) and thermogravimetric (TG) shows that the crystal is stable over the temperature range of 25 to 1364.8 °C with no mass change. It has a wide transmission range from 250 to 4300 nm from UV through the IR region. The useful piezoelectric properties have been characterized, and the results show that it is a promising candidate for high temperature piezoelectric applications.