Magnetic and Mössbauer studies of 5 % Fe-doped BiMnO₃

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• 作者：Alexei A. Belik ; Naoaki Hayashi ; Masaki Azuma ; Shigetoshi Muranaka ; Mikio Takano ; Eiji Takayama-Muromachi
• 关键词：Multiferroics ; Fe-doped BiMnO₃ ; Mö ; ssbauer spectroscopy ; Magnetic susceptibility
• 刊名：Journal of Solid State Chemistry
• 出版年：2007
• 出版时间：December 2007
• 年：2007
• 卷：180
• 期：12
• 页码：3401-3407
• 全文大小：1087 K

文摘

⁵⁷Fe Mössbauer spectroscopy, dc and ac magnetization, specific heat, and differential scanning calorimetry measurements were performed in a powder BiMn_0.95Fe_0.05O₃ sample prepared at 6 GPa and 1383 K. The substitution of 5 % Fe for Mn increases the temperatures of the structural monoclinic-to-orthorhombic phase transition (from 768 to 779 K) and the ferromagnetic transition (from 98 to 109 K) by about 10 K in BiMn_0.95Fe_0.05O₃ compared with BiMnO₃. On the other hand, the temperature of the monoclinic-to-monoclinic phase transition associated with the orbital ordering strongly decreases in BiMn_0.95Fe_0.05O₃ (414 K) compared with that of BiMnO₃ (474 K). The saturated magnetic moment at 5 K and 5 T is also suppressed from 3.92 μ_B per formula unit in BiMnO₃ to 3.35 μ_B in BiMn_0.95Fe_0.05O₃. The large quadrupole splitting (1.18 mm/s) observed at 293 K in BiMn_0.95Fe_0.05O₃ can be explained by the strong Jahn-Teller distortion and cooperative orbital order. The quadrupole splitting reduces by two times above the orbital melting temperature.