Magnetostrictive GMR spin valves with composite FeGa/FeCo free layers

Journal Article · Tue Mar 15 00:00:00 EDT 2016 · AIP Advances

DOI:https://doi.org/10.1063/1.4943770· OSTI ID:22611613

Liu, Luping ^[1]; Zhan, Qingfeng; Yang, Huali; Li, Huihui; Zhang, Shuanglan; Liu, Yiwei; Wang, Baomin; Li, Run-Wei ^[1]; Tan, Xiaohua ^[2]

---

1. Key Laboratory of Magnetic Materials and Devices & Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China)
2. Institute of Materials Science, School of Materials Science and Engineering, Shanghai University, Shanghai 200072 (China)

We have fabricated strain-sensitive spin valves on flexible substrates by utilizing the large magnetostrictive FeGa alloy to promote the strain sensitivity and the composite free layer of FeGa/FeCo to avoid the drastic reduction of giant magnetoresistance (GMR) ratio. This kind of spin valve (SV-FeGa/FeCo) displays a MR ratio about 5.9%, which is comparable to that of the conventional spin valve (SV-FeCo) with a single FeCo free layer. Different from the previously reported works on magnetostrictive spin valves, the SV-FeGa/FeCo displays an asymmetric strain dependent GMR behavior. Upon increasing the lateral strain, the MR ratio for the ascending branch decreases more quickly than that for the descending branch, which is ascribed to the formation of a spiraling spin structure around the FeGa/FeCo interface under the combined influences of both magnetic field and mechanical strain. A strain sensitivity of GF = 7.2 was achieved at a magnetic bias field of -30 Oe in flexible SV-FeGa/FeCo, which is significantly larger than that of SV-FeCo.

• OSTI ID: 22611613
• Journal Information: AIP Advances, Vol. 6, Issue 3; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 2158-3226
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALLOYS
ASYMMETRY
BINARY ALLOY SYSTEMS
COBALT COMPOUNDS
COMPARATIVE EVALUATIONS
COMPOSITE MATERIALS
GALLIUM COMPOUNDS
INTERFACES
IRON COMPOUNDS
LAYERS
MAGNETIC FIELDS
MAGNETORESISTANCE
MAGNETOSTRICTION
SENSITIVITY
SPIN
STRAINS
SUBSTRATES
VALVES