Study of the relationship between magnetic anisotropy and composition ratio of Fe oxide to Fe at CoFeB/MgO film interface
Study of the relationship between magnetic anisotropy and composition ratio of Fe oxide to Fe at CoFeB/MgO film interface
复制标题
CoFeB/MgO薄膜界面磁各向异性与Fe氧化物与Fe成分比关系的研究
DOI：
10.1016/j.apsusc.2022.152697
复制
发表时间：
2022-02
影响因子：
6.7
通讯作者：
Guanghua Yu
中科院分区：
文献类型：
--
作者：
Risi Guo;Xiulan Xu;Yan Ma;Gang Han;Lihua Wang;Jiao Teng;Guanghua Yu
采用磁控溅射法在Si衬底上制备了Ta（5）/CoFeB（1）/MgO（2）/Ta（2）多层膜，并在相同的氩气流量下采用射频（RF）溅射MgO靶和直流（DC）溅射Mg靶同时通氧的反应溅射方法制备了MgO层。将通过前一种方法制备的样品表示为样品A，将后者表示为样品B。结果表明，沉积态样品A具有面内磁各向异性（IMA），Keff= -0.79 × 106 erg/cm 3。而沉积态样品B表现出垂直磁各向异性（PMA），其Keff值为1.69 × 106 erg/cm 3，经250℃退火后，其Keff值增加到3.17 × 106 erg/cm 3。X射线光电子能谱（XPS）结果表明，当样品A和B在300 ℃以下退火时，CoFe B/氧化物界面Fe氧化物与Fe的组成比（ε）在0.65 ~ 0.75之间时，薄膜显示出PMA。当ε超过上述范围时，膜显示IMA。界面处的中等氧化态导致PMA的形成，并通过形成有效的Fe 3d和O2 p轨道杂化而得到改善。高分辨透射电子显微镜（HRTEM）分析表明，退火前后CoFeB和MgO膜层均未发生晶化，晶化对该系统的界面化学态没有影响。
Ta (5)/CoFeB (1)/MgO (2)/Ta (2) (in nm) multilayers were deposited on silicon substrates by magnetron sputtering, and the MgO layer was prepared by two methods at the same argon gas flow rate: the radio frequency (RF) sputtering method of MgO target and the reactive sputtering method of direct current (DC) sputtering Mg target with introducing oxygen at the same time. The sample prepared by the former method was denoted as Sample A, and the latter was denoted as Sample B. The results indicate that as-deposited Sample A shows in-plane magnetic anisotropy (IMA) with Keff= -0.79 × 106erg/cm3. However, the as-deposited Sample B shows perpendicular magnetic anisotropy (PMA) with Keff= 1.69 × 106erg/cm3, and the Keffvalue increases to 3.17 × 106erg/cm3after annealing at 250℃. X-ray photoelectron spectroscopy (XPS) results illustrate that the films show PMA when the composition ratio (ε) of Fe oxide to Fe in CoFeB/oxide interface of Sample A and B annealed below 300 ℃, is approximately in the range of 0.65–0.75. When ε is beyond the above range, the film shows IMA. Moderate oxidation state at the interface results in the formation of PMA and it was improved by forming effective orbital hybridization of Fe 3d and O 2p. High resolution transmission electron microscopy (HRTEM) analysis reveals that no crystallization appears in CoFeB and MgO layer of the film before and after annealing, and crystallization has no effect on the interface chemical states in this system.
登录
查看更多内容
影响因子：
2.4
作者：
Daehoon Kim;Kyung-Woong Park;Byong‐Guk Park
通讯作者：
Daehoon Kim;Kyung-Woong Park;Byong‐Guk Park
影响因子：
19
作者：
Feng, Chun;Wang, Shiru;Yu, Guanghua
通讯作者：
Yu, Guanghua
影响因子：
6.2
作者：
Baldrati, Lorenzo;Rinaldi, Christian;Bertacco, Riccardo
通讯作者：
Bertacco, Riccardo
HfO2对CoFeB/MgO薄膜磁各向异性、电学结构和微观结构的影响
影响因子：
6.2
作者：
Minghua Li
通讯作者：
Minghua Li
氧迁移对垂直 Ta/CoFeB/Gd/MgO/Ta 多层膜磁各向异性和阻尼常数的影响
影响因子：
6.7
作者：
G. Yang;J. Y. Zhang;S. L. Jiang;B. W. Dong;S. G. Wang;J. L. Liu;Y. C. Zhao;W. Wang;Y. Sun;G. H. Yu
通讯作者：
G. H. Yu