Thermal stability of CoFeB/Pt multilayers with perpendicular magnetic anisotropy
Thermal stability of CoFeB/Pt multilayers with perpendicular magnetic anisotropy
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DOI：
10.1063/1.3671776
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发表时间：
2012-02
影响因子：
3.2
通讯作者：
Yanyan Zhu;Zongzhi Zhang;B. Ma;Q. Jin
中科院分区：
文献类型：
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作者：
Yanyan Zhu;Zongzhi Zhang;B. Ma;Q. Jin
研究了[CoFeB/Pt]5多层膜在不同CoFeB厚度（tCoFeB）和固定Pt厚度（10.0）下的垂直各向异性和热稳定性。磁滞回线表现出正方形的2.2-4.0A tCoFeB和适当的CoFeB和Pt厚度的多层膜显示垂直磁各向异性（PMA）。在Ta < 300 °C的温度下进行沉积后退火后，tCoFeB = 2.2 A的环形状没有明显变化，而tCoFeB = 4.5 A的样品由于（111）织构的增强，垂直磁导率随着Ta的增加而增加。在Ta <300 °C时，两个样品的原始方形环开始倾斜，表明PMA劣化的发生与CoFeB厚度无关。XRD结果表明，退火后CoFeB/Pt多层膜中PMA的衰减与CoFeB/Pt界面的互扩散和合金化有关。
The perpendicular anisotropy and thermal stability of [CoFeB/Pt]5 multilayers are investigated with various CoFeB thicknesses (tCoFeB) and a fixed Pt thickness of 10.0 A. Magnetic hysteresis loops exhibit a square shape for 2.2–4.0A tCoFeB and suggest that multilayers with appropriate CoFeB and Pt thicknesses display perpendicular magnetic anisotropy (PMA). After post-deposition annealing at temperatures of Ta < 300 °C, no obvious change occurs in the loop shape for tCoFeB = 2.2 A, while the perpendicular coercivity increases with increasing Ta for the sample with tCoFeB = 4.5 A due to the enhanced (111) texture. At Ta ∼ 300 °C, the original square loops for both samples start to tilt, showing that the occurrence of the PMA degradation is independent of the CoFeB thickness. The XRD results indicate that the observed decay of the PMA in CoFeB/Pt multilayers upon postannealing is associated with the interdiffusion and alloying effects at the CoFeB/Pt interfaces.