Gallium orthophosphate hydrothermal growth at high temperatures (> 320 degrees C)

The specific features of GaPO4 single crystal growth in concentrated soluti ons of phosphoric acids are discussed. The technological scheme of the grow ing process under high temperature hydrothermal conditions is described. Th e growth mechanism of equilibrium and non-equilibrium forms are discussed a s well as the specific features of the shape and crystallographic orientati on of the seeds. As-grown GaPO4 crystals were up to 50 mm in size along the <c > -axis. The study of the growth kinetics in the 300-500 degreesC tempe rature range showed that the growth rates of equilibrium-habit faces were r elated according to the following sequence: pi ' (01 (1) under bar2) > m (1 0 (1) under bar0) > z (01 (1) under bar1) > pi (10 (1) under bar2) > r (10 (1) under bar1).