FLUX GROWTH OF CALCIUM MOLYBDATE CRYSTALS

Calcium molybdate (CaMoO4) crystals were grown from Na2MoO4 and KCl fl uxes by a slow cooling method. At 1100 degrees C, CaMoO4 was dissolved in Na2MoO4 at a concentration of about 37.5 mol%. The eutectic temper ature 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 C aMoO4 bulky crystals of sizes up to 9.0 mm were obtained. The crystal sizes were dependent on the solute content. The most suitable solute c ontent was 30 mol%. The basic form of the crystals was an octahedron b ounded by {112} faces. The CaMoO4 crystals doped with neodymium (CaMoO 4: Nd), up to 6.3 mm in size, were also grown from the Na2MoO4 flux. T he neodymium was incorporated preferentially in the center parts of cr ystals. On the other hand, CaMoO4 had a solubility of about 7.2 mol% i n 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 degre es C h(-1). Colorless and transparent CaMoO4 needle crystals of length s up to 2.5 mm and diameters of 25 mu m were obtained. The most suitab le solute content was 3 mol%. The needle crystals elongated in the < 0 01 > direction. The KCl flux did not produce CaMoO4: Nd needle crystal s.