Reversal of the Pinning Direction in the Synthetic Spin Valve with a NiFeCr Seed Layer

Nanomaterials

卷:12

Shiyang Lu¹  Shaohua Yan²  Weisheng Zhao²  Dapeng Zhu²  Zitong Zhou²  Qunwen Leng²  Zhi Li²  Zhiqiang Cao²  Weibin Chen³ 

[1] Beihang-Goertek Joint Microelectronics Institute, Qingdao Research Institute, Beihang University, Qingdao 266100, China;

[2] School of Integrated Circuit Science and Engineering, Beihang University, Beijing 100191, China;

[3] School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China;

关键词: seed layer;    exchange coupling;    pinning direction;   

DOI  :  10.3390/nano12122077

来源: DOAJ

【 摘 要 】

The effect of the seed layers on the magnetic properties of the giant magnetoresistance thin films has received a lot of attention. Here, a synthetic spin valve film stack with a wedge-shaped NiFeCr seed layer is deposited and annealed following a zero-field cooling procedure. The film crystallinity and magnetic properties are studied as a function of the NiFeCr seed layer thickness. It is found that the exchange coupling field from the IrMn/CoFe interface and the antiferromagnetic coupling field in the synthetic antiferromagnet both increase as the seed layer thickness increases, indicating the perfection of film texture. In this film, the critical thickness of the NiFeCr seed layer for the formation of the ordered IrMn₃ texture is about 9.3 nm. Meanwhile, a reversal of the pinning direction in the film is observed at this critical thickness of NiFeCr. This phenomenon can be explained in a free energy model by the competition effect between the exchange coupling and the interlayer coupling during the annealing process.

【 授权许可】

Unknown