Effect of Bivalent Cation Ca-Doping on Magnetic Properties in Multiferroic YMnO3 Manganites
Effect of Bivalent Cation Ca-Doping on Magnetic Properties in Multiferroic YMnO3 Manganites
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DOI：
10.1007/s10948-009-0623-1
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发表时间：
2010-01
影响因子：
1.8
通讯作者：
Yuling Su;Z. Chen;Yuefeng Li;D. Deng;S. Cao;Jincang Zhang
中科院分区：
文献类型：
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作者：
Yuling Su;Z. Chen;Yuefeng Li;D. Deng;S. Cao;Jincang Zhang
通过直流和交流磁测量系统地研究了二价阳离子钙掺杂对多铁性锰锰酸盐磁性能的影响。采用固相反应法制备了Y1−xCaxMnO3（x=i/8,i=2,3，…，7）系列样品。结果表明，随着ca掺杂量的增加，各零场冷却曲线有明显的尖峰，并向更高的温度偏移。由χ−1 - t曲线可知，CO态的温度约为244.0 K，表明具有小a位阳离子的y1 / 2ca1 / 2mno3的CO态主要受协同Jahn-Teller效应支配，其行为与其他较大的<rA>的锰酸盐不同。对于Y1−xCaxMnO3，当x=2/8和7/8时，磁化曲线在ZFC和FC数据之间表现出很强的不可逆性。交流磁化率的变化在ZFC和ZF曲线分岔的起始温度处出现最大值，并随着交流磁化率测量频率的增加而向更高温度转移。这些结果可以用自旋玻璃来表征，表明更多的流动电子正在促进磁转变。
Effect of bivalent cation Ca-doping on magnetic properties in multiferroic YMnO3manganites was systemically studied by DC and AC magnetic measurements. Series of samples were prepared by solid-state reaction method with composition Y1−xCaxMnO3(x=i/8,i=2,3,…,7). The results show that each of the zero-field-cooling (ZFC) curves has a clear cusp and it shifts to higher temperature with increasing Ca-dopingx. From theχ−1–Tcurve, the temperature of charge-ordering (CO) stateTCOis given at about 244.0 K and this indicates that the CO state is dominated by the cooperative Jahn–Teller effect in Y1/2Ca1/2MnO3with small A-site cation, for which there is a different behavior compared to the other manganites of larger <rA>. Whenx=2/8 and 7/8 for Y1−xCaxMnO3, the magnetization curve shows strong irreversibility between ZFC and FC data. The variation of AC susceptibility presents a maximum cusp at the beginning temperature of the bifurcation between ZFC and ZF curve and shifts to higher temperature with increasing measurement frequency for AC susceptibility. These results can be characterized by spin-glass, indicating that much more itinerant egelectrons are promoting the magnetic transition.