Local electronic structure and magnetic properties of LaMn0.5Co0.5O3 studied by x-ray absorption and magnetic circular dichroism spectroscopy
Local electronic structure and magnetic properties of LaMn0.5Co0.5O3 studied by x-ray absorption and magnetic circular dichroism spectroscopy
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DOI：
10.1103/physrevb.77.125124
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发表时间：
2008-03-01
影响因子：
3.7
通讯作者：
Tjeng, L. H.
中科院分区：
文献类型：
--
作者：
Burnus, T.;Hu, Z.;Tjeng, L. H.
我们利用软x射线吸收光谱研究了LaMn0.5Co0.5O3在Co-L-3,L-2和Mn-L-3,L-2边缘的局域电子结构。我们发现具有最佳居里温度的样品具有高自旋 Co2+-Mn4+ 价态。我们发现居里温度较低的样品含有低自旋非磁性 Co3+ 离子。利用软 X 射线磁圆二色性，我们确定 Co2+ 和 Mn4+ 离子是铁磁性排列的。我们还发现 Co2+ 离子具有很大的轨道矩：morb/mspin 大约为 0.47。结合模型计算，这表明材料中存在较大的磁晶各向异性，并预测磁化率与温度的相关性。
We have studied the local electronic structure of LaMn0.5Co0.5O3 using soft-x-ray absorption spectroscopy at the Co-L-3,L-2 and Mn-L-3,L-2 edges. We found a high-spin Co2+-Mn4+ valence state for samples with the optimal Curie temperature. We discovered that samples with lower Curie temperatures contain low-spin nonmagnetic Co3+ ions. Using soft-x-ray magnetic circular dichroism, we established that the Co2+ and Mn4+ ions are ferromagnetically aligned. We also revealed that the Co2+ ions have a large orbital moment: morb/mspin approximate to 0.47. Together with model calculations, this suggests the presence of a large magnetocrystalline anisotropy in the material and predicts a nontrivial temperature dependence for the magnetic susceptibility.