Growth of Millimeter-sized Platy Single Crystals of NaTaO3 from Na2MoO4 Flux

Perovskite-type NaTaO3 is best known as a semiconductor photocatalyst that splits water under ultraviolet (UV) light irradiation. Here, we report the flux growth of millimeter-sized, platy NaTaO3 crystals using Na2MoO4 as the flux. During flux growth, the crystal size and the number of anisotropic crystals increased as the holding temperature was increased from 1100 to 1500 °C. By slowly cooling from 1500 to 1300 °C at a rate of 5 °C·h–1, rectangular platy crystals grew up to 8.0 mm × 4.7 mm × 0.044 mm. The grown NaTaO3 crystals belonged to orthorhombic system and the index of the well-developed faces was {010}.