Mi Chun-Wei, Chin Yi-Ying, Hsiao Yen-Fu, Fang Hau-Wei, Luo Chih-Wei, Wu Kaung-Hsiung, Uen Tzeng-Ming, Lin Jiunn-Yuan, Lin Hong-Ji, Juang Jenh-Yih
Department of Electrophysics, National Chiao Tung University, Hsinchu 30010, Taiwan.
J Phys Condens Matter. 2016 Sep 1;28(34):345501. doi: 10.1088/0953-8984/28/34/345501. Epub 2016 Jun 29.
The electronic structure and magnetic properties of SrMn0.5Fe0.5O3 powder and films grown on (1 0 0)-SrTiO3 (STO) and (1 0 0)-LaAlO3 (LAO) substrates by pulsed laser deposition (PLD) were investigated by temperature dependent magnetization and soft x-ray absorption. The results exhibit characteristics of 3d (5) Fe(3+), [Formula: see text], and 3d (3) + 3d (4) [Formula: see text] Mn(4+) at room temperature in all samples. However, the features of 3d (5) Fe(3+) and 3d (3) Mn(4+) increased significantly for SMFO/LAO at 35 K, which also displayed substantial competition between antiferromagnetic and ferromagnetic order well-above the Néel temperature of SrFeO3 (T N ~ 134 K). We attributed this to being caused by charge disproportionation resulting from ligand-hole localization, which is more favorable to take place when the sample is under compressive strain.
通过变温磁化和软X射线吸收研究了通过脉冲激光沉积(PLD)在(1 0 0)-SrTiO3(STO)和(1 0 0)-LaAlO3(LAO)衬底上生长的SrMn0.5Fe0.5O3粉末和薄膜的电子结构和磁性。结果表明,在室温下所有样品中均呈现出3d(5)Fe(3+)、[化学式:见原文]以及3d(3)+3d(4)[化学式:见原文]Mn(4+)的特征。然而,对于SMFO/LAO,在35 K时3d(5)Fe(3+)和3d(3)Mn(4+)的特征显著增强,这也表明在远高于SrFeO3的奈尔温度(TN~134 K)时,反铁磁和铁磁序之间存在显著竞争。我们将此归因于配体空穴局域化导致的电荷歧化,当样品处于压缩应变时,这种电荷歧化更易于发生。