Flux growth of calcium molybdate crystals

Calcium molybdate (CaMoO4) crystals were grown from Na2MoO4 and KCl fluxes by a slow cooling method. At 1100 degrees C, CaMoO4 was dissolved in Na2MoO4 at a concentration of about 37.5 mol%. The eutectic temperature was 675+/-5 degrees C. The Na2MoO4 flux growth was conducted by heating mixtures at 1100 degrees C for 5 h, followed by cooling to 450 degrees C at a rate of 5 degrees C h(-1). Colorless and transparent CaMoO4 bulky crystals of sizes up to 9.0 mm were obtained. The crystal sizes were dependent on the solute content. The most suitable solute content was 30 mol%. The basic form of the crystals was an octahedron bounded by {112} faces. The CaMoO4 crystals doped with neodymium (CaMoO4: Nd), up to 6.3 mm in size, were also grown from the Na2MoO4 flux. The neodymium was incorporated preferentially in the center parts of crystals. On the other hand, CaMoO4 had a solubility of about 7.2 mol% in KCl at 900 degrees C. The eutectic temperature was 725+/-5 degrees C. The KCl flux growth was conducted by heating mixtures at 900 degrees C for 10 h, followed by cooling to 500 degrees C at a rate of 5 degrees C h(-1). Colorless and transparent CaMoO4 needle crystals of lengths up to 2.5 mm and diameters of 25 mu m were obtained. The most suitable solute content was 3 mol%. The needle crystals elongated in the < 001 > direction. The KCl flux did not produce CaMoO4: Nd needle crystals.