Magnetic tunneling junction based magnetic field sensors: Role of shape anisotropy versus free layer thickness

被引：11

作者：

Shah, Lubna R. ^{[1
]}

Bhargava, Nupur ^{[2
]}

Kim, Sangcheol ^{[2
]}

Stearrett, Ryan ^{[1
]}

Kou, Xiaoming ^{[1
]}

Sun, Xiaolian ^{[3
]}

Sun, Shouheng ^{[3
]}

Kolodzey, James ^{[2
]}

Nowak, Edmund R. ^{[1
]}

Xiao, John Q. ^{[1
]}

机构：

[1] Univ Delaware, Dept Phys & Astron, Newark, DE 19716 USA

[2] Univ Delaware, Dept Elect & Comp Engn, Newark, DE 19716 USA

[3] Brown Univ, Dept Chem, Providence, RI 02912 USA

来源：

JOURNAL OF APPLIED PHYSICS | 2011年 / 109卷 / 07期

关键词：

D O I：

10.1063/1.3563096

中图分类号：

O59 [应用物理学];

学科分类号：

摘要：

Al2O3- and MgO-based magnetic tunnel junction (MTJ) sensors were designed and fabricated using microfabrication techniques. This study revealed that in the case of Al2O3-based sensors, the shape anisotropy in the free NiFe electrode resulted in a linear and hysteresis-free tunneling magnetoresistance (TMR) curve. These sensors exhibited TMR values between 27% and 30% and sensitivity up to 0.4%/Oe over a magnetic field range of -40 to 40 Oe. In the case of CoFeB/MgO/CoFeB MTJ sensors, shape anisotropy alone was not sufficient to achieve a linear and hysteresis-free MR response. A superparamagnetic free layer was used to achieve the desired sensor response. MgO-based sensors had about 90% TMR and 1.1%/Oe sensitivity over the same field range as Al2O3-based MTJs. (C) 2011 American Institute of Physics. [doi:10.1063/1.3563096]

引用

页数：3

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