Hongbing Chen
材料科学技术（英文）
The growth of LaBr3:Ce3+ crystal by the vertical Bridgman process in a nonvacuum atmosphere was reported. According to the dehydration procedure of LaBr3·7H2O and CeBr3·7H2O investigated by differential thermal analysis/thermogravimetry (DTA/TG), anhydrous LaBr3 and CeBr3 were prepared by heating LaBr3·7H2O and CeBr3·7H2O at 240-260°C for 5-6 h in dried HBr atmosphere. Using the feed materials prepared from the anhydrous lanthanon bromides, a 0.5 mole fraction Ce3+ doped LaBr3 crystal with size of Φ25 mm×50 mm had been grown by vertical Bridgman process successfully. By sealing the feed material in a platinum crucible, the crystal could be grown in a nonvacuum atmosphere as the oxidization and volatilization of the melt could be avoided. The crystal was grown with the optimum conditions such as a growth rate of 0.5-1.0 mm/h and a temperature gradient of around 30°C/cm across solid-liquid interface under a furnace temperature of 850-880°C. The crystal was characterized by DTA/TG, X-ray diffraction (XRD), optical transmission, photoluminescence and X-ray stimulated luminescence measurement. The Bridgman process was confirmed to be promising for growing transparent LaBr3:Ce3+ crystal with high optical quality.
关键词:
LaBr3 ∶Ce3+
,
Scintillator
,
Dehydration
,
Crystal growth
,
Bridgman process
