Tunneling magnetoresistance sensors with different coupled free layers

Authors

Yen-Fu Liu, University of Nebraska - Lincoln
Xiaolu Yin, University of Nebraska - Lincoln
Yi Yang, University of Nebraska - LincolnFollow
Dan Ewing, Department of Energy's National Security Campus, Kansas City, Missouri
Paul J. De Rego, Department of Energy's National Security Campus, Albuquerque, New Mexico
Sy-Hwang Liou, University of Nebraska-LincolnFollow

Date of this Version

2017

Citation

AIP Advances 7, 056666 (2017)

Comments

© 2017 Author(s).

Open access

https://doi.org/10.1063/1.4977774

Abstract

Large differences of magnetic coercivity (HC), exchange coupling field (HE), and tun- neling magnetoresistance ratio (TMR) in magnetic tunnel junctions with different coupled free layers are discussed. We demonstrate that the magnetization behavior of the free layer is not only dominated by the interfacial barrier layer but also affected largely by the magnetic or non-magnetic coupled free layers. All these parameters are sensitively controlled by the magnetic nanostructure, which can be tuned also by the magnetic annealing process. The optimized sensors exhibit a large field sensitivity of up to 261%/mT in the region of the reversal synthetic ferri- magnet at the pinned layers.