Magnetic phase transitions and magnetoelectric coupling of GdFeO3 single crystals probed by low-temperature heat transport
Magnetic phase transitions and magnetoelectric coupling of GdFeO3 single crystals probed by low-temperature heat transport
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DOI：
10.1103/physrevb.83.014414
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发表时间：
2011-01-18
影响因子：
3.7
通讯作者：
Sun, X. F.
中科院分区：
文献类型：
--
作者：
Zhao, Z. Y.;Wang, X. M.;Sun, X. F.
发现GdFeO 3单晶的低温热导率（kappa）强烈依赖于磁场。低场kappa（H）曲线显示了平行于a的H的两个“凹陷”和平行于c的H的仅一个凹陷，其中特征场与自旋翻转和自旋极化转变具有良好的对应性。一个值得注意的现象是，亚开尔文热导率在施加磁场的历史上表现出滞后行为;即，随着磁场的增加测量的kappa（H）等温线大于随着磁场的减小测量的kappa（H）等温线。有趣的是，显示热传输不可逆性的宽磁场区域（类似于0-3 T）与呈现铁电性的区域相一致。讨论了不可逆的Kappa（H）行为是由于铁电畴壁对声子的散射。这一结果表明了磁场控制多铁性材料铁电畴结构的实验特征。
The low-temperature thermal conductivity (kappa) of GdFeO3 single crystals is found to be strongly dependent on magnetic field. The low-field kappa(H) curves show two "dips" for H parallel to a and only one dip for H parallel to c, with the characteristic fields having good correspondence with the spin-flop and the spin-polarization transitions. A remarkable phenomenon is that the sub-Kelvin thermal conductivity shows hysteretic behaviors on the history of applying the magnetic field; that is, the kappa(H) isotherms measured with increasing field are larger than those with decreasing field. Intriguingly, the broad region of magnetic field (similar to 0-3 T) showing the irreversibility of heat transport coincides with that presenting the ferroelectricity. It is discussed that the irreversible kappa(H) behaviors are due to the phonon scattering by ferroelectric domain walls. This result shows an experimental feature that points to the capability of controlling the ferroelectric domain structures by magnetic field in multiferroic materials.