Site-Selective Doping Effect in AMn3V4O12 (A = Na+, Ca2+, and La3+)

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• 作者：Shoubao Zhang ; Takashi Saito ; Masaichiro Mizumaki ; Wei-tin Chen ; Takenori Tohyama ; Yuichi Shimakawa
• 刊名：The Journal of the American Chemical Society
• 出版年：2013
• 出版时间：April 24, 2013
• 年：2013
• 卷：135
• 期：16
• 页码：6056-6060
• 全文大小：299K
• 年卷期：v.135,no.16(April 24, 2013)
• ISSN：1520-5126

文摘

A-site-ordered perovskite-structure oxides with Mn and V at A鈥?and B sites, respectively, were synthesized by using a high-pressure method. Valence-state analyses revealed that the A-site substitution modulated the valence states of the Mn ions at the A鈥?site and V ions at the B site sequentially. By changing the A-site ions from Na⁺ to Ca²⁺ and from Ca²⁺ to La³⁺, the valence distribution changed site-selectively from Na⁺Mn^2.33+₃V⁴⁺₄O₁₂ to Ca²⁺Mn²⁺₃V⁴⁺₄O₁₂ and to La³⁺Mn²⁺₃V^3.75+₄O₁₂. The electrons of the A鈥?site Mn were localized and contributed to the magnetic properties, that is, spin-glass-like behavior in NaMn₃V₄O₁₂ and antiferromagnetic behavior in CaMn₃V₄O₁₂ and LaMn₃V₄O₁₂. The valence electrons of the B-site V, in contrast, were delocalized, as could be seen from the low resistivity of the samples. The delocalized electrons at the B-site V did not correlate with the localized spins at the A鈥?site Mn.