Growth of LaBr₃:Ce³⁺ Single Crystal by Vertical Bridgman Process in Nonvacuum Atmosphere

Hongbing Chen1), Changyong Zhou1), Peizhi Yang2) and Jinhao Wang1) 1) State Key Laboratory Base of Novel Functional Materials & Preparation Science, Institute of Materials Science & Engineering, Ningbo University, Ningbo 315211, China 2) Key Laboratory of Advanced Technique & Preparation for Renewable Energy Materials, Ministry of Education, Yunnan Normal University, Kunming 650092, China

摘 要：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.

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