Influence of Annealing on the Optical Properties of PbWO4 Single Crystals Grown by the Bridgman Method
Abstract
In the present work, the evaporation rate of PbWO4 (PWO, powdered crystal) and PbO (powder) in the temperature range of 700 to 1200°C was measured by thermogravimetric analysis. The log V vs T-1 plot was determined to be linear and the temperature dependence of the evaporation rate of PWO was found to be the same as that of PbO in the solid state. This shows that the crystals grown by the Czochralski method are Pb-deficient as a result of self-annealing. The optical transmittance and the excitation-emission spectra of the as-grown and annealed PWO crystals grown by the Bridgman method were also measured. Annealing was performed in the temperature range of 500 to 1000°C (isochronal) for 1 h. The surface emission of the annealed samples exhibited a particularly strong peak at 485 nm whose intensity decreased with increasing annealing temperature. The transmittance was found to exhibit a small but consistent increase with increasing annealing temperature at about 350 nm.
- Publication:
-
Japanese Journal of Applied Physics
- Pub Date:
- September 2000
- DOI:
- 10.1143/JJAP.39.5134
- Bibcode:
- 2000JaJAP..39.5134S