Structural and magnetoelectric properties of Ga2-xFexO3 single crystals grown by a floating-zone method
Structural and magnetoelectric properties of Ga2-xFexO3 single crystals grown by a floating-zone method
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DOI：
10.1103/physrevb.70.064426
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发表时间：
2004-08-01
影响因子：
3.7
通讯作者：
Tokura, Y
中科院分区：
文献类型：
--
作者：
Arima, T;Higashiyama, D;Tokura, Y
对采用浮区法（FZ）生长的典型极性亚铁磁体Ga₂₋ₓFeₓO₃（0.8≤x≤1.4）单晶的晶格结构、磁性以及磁电（ME）特性进行了研究。磁化测量表明，饱和磁化强度以及亚铁磁相变温度（T₆）随Fe含量x的增加而升高，而矫顽力降低。中子粉末衍射研究表明，阳离子位点处Ga和Fe排列的有序度相当低，这可能与FZ晶体中的T₆低于相应的助熔剂生长晶体有关。通过测量扫磁场诱导的电极化变化，得到了线性和二次磁电效应系数。在平行于自发磁化方向施加的磁场中，电极化被大幅调制，但在平行于自发极化方向的磁场中则没有。提出了一个简单的模型来解释这种鲜明的对比。
Lattice-structural, magnetic, and magnetoelectric (ME) properties have been investigated for single crystals of prototypical polar ferrimagnet Ga2-xFexO3 (0.8less than or equal toxless than or equal to1.4) as melt-grown by a floating-zone (FZ) method. Magnetization measurements show that the saturated magnetization as well as the ferrimagnetic phase transition temperature (T-C) increases with as increase of Fe content x, while the coercive force decreases. A neutron powder diffraction study indicates fairly low ordering of Ga and Fe arrangement at cation sites, which is likely related to the lower T-C in the FZ crystals than in the corresponding flux-grown crystals. Coefficients of linear and quadratic ME effects have been obtained with measurements of change in electric polarization induced by sweeping a magnetic field. Electric polarization was largely modulated in a magnetic field applied parallel to the direction of spontaneous magnetization, but not in a field parallel to that of the spontaneous polarization. A simple model to explain the sharp contrast is presented.