Influence of heat treatment on the structural and optical properties of SrGd_2O_4:Eu^(3+) phosphor

作     者：Jyoti Singh Pankaj Kr.Baitha J.Manam 

作者机构：Department of Applied Physics Indian School of Mines 

出 版 物：《Journal of Rare Earths》 (稀土学报（英文版）)

年 卷 期：2015年第33卷第10期

页      面：1040-1050页

核心收录：

学科分类：081702[工学-化学工艺] 0709[理学-地质学] 0819[工学-矿业工程] 08[工学] 0817[工学-化学工程与技术] 0708[理学-地球物理学] 0703[理学-化学] 

基　　金：Project supported by ISM Research Scholars Funding by Government of India 

主　　题：optical materials chemical synthesis X-ray diffraction luminescence rare earths 

摘      要：Novel red emitting Eu3＋ doped SrGd2O4 phosphors were synthesized by homogeneous precipitation method followed by a subsequent combustion process at various temperatures. A systematic study on the consequent structural evolution and optical properties were investigated as a function of various processing temperatures. With the enhancement of processing temperature, SrGd2O4 phosphor showed a gradual transformation from a mixed phase to monophasic nature, with minimized volatile imptwities. The microscopic images exhibited homogeneous aggregates of varying shapes and sizes with an average length of about 0.5-5μl. Eu3＋ doped SrGd2O4 phosphors prepared at low temperatures, showed miserably low values of red emission upon UV excitation owing to the presence of volatile impurities. The SrGd2O4：Eu3＋ phosphors prepared at relatively high temperature exhibited strong red-orange emissions due to homogeneously occupied Eu3＋ ions in the host lattice. The dominant red to orange （R/O） emission intensity ratios and CIE parameters of EU3＋ ions substantiated the site occupation of higher asymmetry sites of Gd3＋ ions and the strong covalent nature. Dexter theory and critical distance calculation suggested that the dipole-dipole interaction could be responsible for the concentration quenching of Eu3＋ （4 mol.%） doped SrGd2O4 phosphors. Elevated physical and chemical durability and stable photoluminescence made these phosphors suitable for white LEDs and other display applications.