Experimental Study on the Coloration of PbWO_4 Crystal

Based on the experiments, some coloration phenomena in PbWO4 crystals grown from the mixture of PbO and WO3 powders by a modified Bridgman method were reported. Through analyzing these experimental phenomena, it was proposed that both defects of VO and VPb exist in the PbWO4 crystals, and that Vo leads to the decrease of transmission at 350nm whereas the existence of VPb is the main cause which results in the coloration of the crystal and absorption band at 420nm.