Luminescence Properties of Lanthanide and Transition Metal Ion-Doped Ba2LaNbO6: Detection of MnO68− and CrO69− Clusters

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• 作者：Peter A. Tanner ; Zaifa Pan
• 刊名：Inorganic Chemistry
• 出版年：2009
• 出版时间：December 7, 2009
• 年：2009
• 卷：48
• 期：23
• 页码：11142-11146
• 全文大小：754K
• 年卷期：v.48,no.23(December 7, 2009)
• ISSN：1520-510X

文摘

The as-prepared double-perovskite Ba₂LaNbO₆ (space group I2/m at ambient temperatures) exhibited an unexpected well-resolved red luminescence, which was found to arise from parts-per-million impurity of Mn⁴⁺. The ions Mn⁴⁺ or Cr³⁺ doped into this host are situated at Nb⁵⁺ sites with slightly distorted octahedral symmetry, with the distortion greater for the case of greater charge mismatch. The Stokes luminescence spectra of the dopant ions comprise ν₃, ν₄, and ν₆ moiety mode vibronic origins, and the high vibrational frequency ratio ν₄/ν₃ signals the stiffness of the O−M−O (M = Mn, Cr) angle in the double perovskite. The site symmetry at the La³⁺ site of lanthanide ions doped into Ba₂LaNbO₆ comprises a 2-fold axis at most. All dopant ions exhibit concentration quenching in this lattice.