Crystal Growth of Low Dimensional Spin Systems

Abstract

Crystal growth of the quasi-low dimensional spin systems (VO)2P2O7, LiCuVO4, a-CuV2O6 and CuSb2O6 is reported. All substances are characterized by different kinds of instabilities. Vanadyl pyrophosphate either oxidizes in air or reduces in an inert atmosphere. It can be grown, however, from the melt in a special atmosphere, containing 0.1-0.7 mol.% of oxygen. The other compounds decompose before melting inevitably. Therefore techniques allowing growth at lower temperature were applied. Crystals of LiCuVO4 and a-CuV2O6 were grown from a flux. Corresponding phase diagrams solute-solvent were determined. For growth of CuSb2O6 crystals a chemical vapour transport technique was developed. The chemical processes in the gaseous phase were analyzed using thermodynamical calculations. The grown crystals were characterized by X-ray diffractometry and scanning electron microscopy with energy/wavelength dispersive X-ray analysis.