Large enhancement of Blocking temperature by control of interfacial structures in Pt/NiFe/IrMn/MgO/Pt multilayers
Large enhancement of Blocking temperature by control of interfacial structures in Pt/NiFe/IrMn/MgO/Pt multilayers
复制标题
通过控制 Pt/NiFe/IrMn/MgO/Pt 多层膜的界面结构大幅提高阻断温度
DOI：
10.1063/1.4931163
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发表时间：
2015
期刊：
影响因子：
1.6
通讯作者：
G. H. Yu
中科院分区：
文献类型：
--
作者：
X. Chen;S. G. Wang;G. Han;S. L. Jiang;K. Yang;Q. Q. Liu;J. L. Liu;R. M. Wang;G. H. Yu
在IrMn/MgO界面处插入1 nm厚的Mg层，使Pt/NiFe/IrMn/MgO/Pt多层膜的阻滞温度（TB）从远低于室温（RT）提高到高于室温（TB）。此外，界面结构的控制也增加了交换偏置场（Heb）。x射线光电子能谱分析表明，在没有Mg插入层的IrMn/MgO界面上存在较大比例的Mn-O键。Mn与O之间的键合降低了IrMn薄膜的反铁磁性，导致Pt/NiFe/IrMn/MgO/Pt多层膜中TB值降低。在IrMn/MgO界面处插入超薄Mg膜作为氧沉层，可以抑制Mn和O之间的氧化反应，大大减少Mn-O键的形成。氧化抑制使IrMn膜的反铁磁性得到恢复，从而增强了TB和Heb。此外，高分辨率透射电子显微镜还证实了镁插入层可以有效地提高材料的稳定性。
The Blocking temperature (TB) of Pt/NiFe/IrMn/MgO/Pt multilayers was greatly enhanced from far below room temperature (RT) to above RT by inserting 1 nm thick Mg layer at IrMn/MgO interface. Furthermore, the exchange bias field (Heb) was increased as well by the control of interfacial structures. The evidence for a significant fraction of Mn-O bonding at IrMn/MgO interface without Mg insertion layer was provided by X-ray photoelectron spectroscopy. The bonding between Mn and O can decrease the antiferromagnetism of IrMn film, leading to lower value of TB in Pt/NiFe/IrMn/MgO/Pt multilayers. Ultrathin Mg film inserted at IrMn/MgO interface acting as an oxygen sinking layer can suppress the oxidation reactions between Mn and O and reduce the formation of Mn-O bonding greatly. The oxidation suppression results in the recovery of the antiferromagnetism of IrMn film, which can enhance TB and Heb. Furthermore, the high resolution transmission electron microscopy demonstrates that the Mg insertion layer can effic...