Crystal structure of Eu-doped magnetoplumbite-type lanthanum aluminum oxynitride with emission site splitting

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• 作者：Yuji Masubuchi  ; ;   ; ^{yuji-mas@eng.hokudai.ac.jp} ; Tomoyuki Hata ; Teruki Motohashi ; Shinichi Kikkawa
• 关键词：Lanthanum aluminum oxynitride ; Magnetoplumbite structure ; Photoluminescence ; Neutron diffraction
• 刊名：Journal of Solid State Chemistry
• 出版年：2011
• 出版时间：September 2011
• 年：2011
• 卷：184
• 期：9
• 页码：2533-2537
• 全文大小：569 K

文摘

Eu-doped lanthanum aluminum oxynitride (LaAl₁₂(O,N)₁₉) with magnetoplumbite structure was prepared by nitridation of the oxide precursor obtained from aluminum glycine gel and subsequent post-annealing. Eu-doped lanthanum aluminum oxynitride exhibited blue light emission at 440 nm with a shoulder at 464 nm under excitation at 254 nm. Isostructural Eu-doped calcium aluminum oxide (CaAl₁₂O₁₉) exhibited a single emission peak at 415 nm. Structural refinement using neutron powder diffraction indicated that the lanthanum site occupied partially by Eu²⁺ splits into 2d and 6h sites in the aluminum oxynitride. The longer emission and the shoulder peak in the former aluminum oxynitride were observed in relation to the increasing covalency as well as crystal field splitting around doped Eu²⁺ induced by site splitting involved with the two kinds of anions.