Laser-induced infrared absorption in lead tungstate observed by laser-SR combined spectroscopy

摘要

Transient infrared absorption measurements are performed to study the photo-induced states in PbWO_4 crystals at 16K. A broad band is observed above 4000 cm~(-1), with a peak around 9000cm~(-1). This band has a lifetime of 50ms at 16K, and disappears when the sample temperature is increased above 25 K. To investigate the origin of the photo-induced states, thermoluminescence is also measured after prolonged irradiation with 7.7-eV light at 8 K. Three glow peaks are observed at 15, 30, and 53 K. It is pointed out that the photo-induced band has a correlation with the 15-K glow peak, and is attributed to the (WO_4)~(3-) complex perturbed by another defect at the nearest-neighbor site.