Mössbauer Studies and Magnetic Properties of Y_3–xCe_xFe₅O₁₂

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• 作者：Jun Sig Kum ; Sam Jin Kim ; In Bo Shim and Chul Sung Kim
• 关键词：superexchange interaction ; M?ssbauer spectroscopy ; Debye temperature ; coercivity ; Ce doped garnet
• 刊名：Hyperfine Interactions
• 出版年：2004
• 出版时间：March 2004
• 年：2004
• 卷：156-157
• 期：1-4
• 页码：169-174
• 全文大小：117 KB

文摘

Magnetic and crystallographic properites of Y_3−x Ce _x Fe₅O₁₂ (x=0.0, 0.1, and 0.3) have been studied with X-ray diffraction, vibrating sample magnetometer (VSM), and M?ssbauer spectroscopy. A small coercivity (H _c =5.8 Oe), was obtained for the sample Y_2.9Ce_0.1Fe₅O₁₂, which is comparable to that of an undoped sample Y₃Fe₅O₁₂ (H _c =54.1 Oe). M?ssbauer spectra of Y_3−x Ce _x Fe₅O₁₂ were measured at various absorber temperatures from 4.2 K to N¨¦el temperature. It is found that Debye temperatures of octahedral (16a) and tetrahedral (24d) site for Y_2.9Ce_0.1Fe₅O₁₂ are Θ _a =353, Θ _d =464 K, respectively, and for Y_2.7Ce_0.3Fe₅O₁₂, Θ _a =380, Θ _d =444 K, respectively. The intersublattice a–d superexchange interaction was found to be antiferromagnetic with the strength of J _a−d =−21.42 k _B, while the intrasublattice interactions a–a, d–d were found to be ferromagnetic with strengths of J _a–a =4.50 k _B and J _d–d =0.02k _B , respectively, in the sample Y_2.9Ce_0.1Fe₅O₁₂.