Crystal growth and electrical properties of CaSO4:Dy single crystals

Single crystals of CaSO₄:Dy, with and without charge compensator were grown by the solution growth technique. Electrical conductivity was studied at room temperature for diverse concentrations of Dysprosium and showed that it increases upto 0.2 wt % of Dy, beyond which saturation sets in. Electrical conductivity was studied in the region 400 to 700°K and the migration energies estimated for various dopant concentrations. The variation of electrical conductivity and migration energy with diverse dopent concentration is explained on the basis of the theory of defects. The thermoelectric power measurements reveal that the crystals grown are ofP type.