Photoluminescence of Tb-doped MgAl-LDHs depending on phase transition caused by annealing

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• 作者：Yufeng CHEN ((陈玉凤)) ; ^{yfchen@ncu.edu.cn" class="auth_mail" title="E-mail the corresponding author} ; Yao BAO ((鲍 垚)) ; Zhipeng YU ((余志鹏)) ; Guangchao YANG ((杨广超)) ; Xiaoqing WANG ((王肖庆))
• 关键词：MgAl-LDH ; Tb-doped ; phase transition ; photoluminescence ; annealing ; rare earths
• 刊名：Journal of Rare Earths
• 出版年：2016
• 出版时间：January 2016
• 年：2016
• 卷：34
• 期：1
• 页码：36-44
• 全文大小：2232 K

文摘

This paper presented the photoluminescence of Tb-doped Mg-Al layered double hydroxides (Tb-doped MgAl-LDHs) depending on phase transition caused by annealing. Tb-doped MgAl-LDHs structure transformed from hexagonal LDHs, cubic MgO to spinel MgAl₂O₄ phase as temperature varied from 200 to 1000 °C. Emission and excitation spectra of Tb-doped MgAl-LDHs obviously changed with phase transformation. The emissions of Tb³⁺ ions attributed to ⁵D₄→⁷F_J transitions (J=3, 4, 5, 6) were observed in the emission spectra of all the Tb-doped samples. The ratio of (⁵D₄→⁷F₅)/(⁵D₄→⁷F₆) emission intensity, which was sensitive to surroundings of Tb³⁺ ion, markedly enhanced with temperature rising to 600 from 400 °C. Over 600 °C, the ratio of (⁵D₄→⁷F₅)/(⁵D₄→⁷F₆) intensity tended to decreasing up to 1000 °C. The change concerning the ratio of the (⁵D₄→⁷F₅)/(⁵D₄→⁷F₆) emission intensity might be due to various surroundings of Tb³⁺ induced by phase transformation.