The morphology of Zn3P2 single crystals grown from the vapour phase

The morphology of Zn₃P₂ single crystals, grown from the vapour phase by sublimation of bulk Zn₃P₂ in a sealed quartz tube pulled through a high temperature gradient, has been investigated. X-ray diffraction examination showed that the main direction of crystal growth with a tetragonal unit cell is the 021] direction which corresponds to the 111] direction in the pseudocubic system. Transverse and longitudinal cross sections of the single crystals were mechanically polished and chemically etched. Optical examination of the cross sections indicated that the growth of Zn₃P₂ begins most frequently in the (011) plane. Striae which appeared in a cross section after chemical etching are attributed to the existence of strain fields generated in the sample as a result of temperature fluctuations or as a result of crystal structure defects in the core region.