AVS 54th International Symposium | |
Magnetic Interfaces and Nanostructures | Friday Sessions |
Session MI-FrM |
Session: | Spin Injection, Transfer, and Tunneling |
Presenter: | Z.R. Tadisina, The University of Alabama |
Authors: | Z.R. Tadisina, The University of Alabama S. Gupta, The University of Alabama A. Highsmith, The University of Alabama P. LeClair, The University of Alabama T. Mewes, The University of Alabama G.B. Thompson, The University of Alabama |
Correspondent: | Click to Email |
The magnetic properties of current-perpendicular-to-the-plane (CPP) giant magnetoresistive (GMR) spin valves employing synthetic antiferromagnet (SAF) pinning have been investigated. The standard CPP spin valve structure, with a ferromagnetic (F) layer pinned by an antiferromagnet (AF), exhibits high electrical resistance, the antiferromagnet typically being a high resistivity material. We have investigated pinning with a Co/Ru/Co SAF trilayer only, with no additional AF pinning. Elimination of the AF-induced parasitic resistance yields a higher GMR ratio. The full-film properties have been optimized using vibrating sample magnetometry (VSM) and current-in-plane (CIP) magnetotransport measurements, and related to CPP spin valve properties after patterning. A theoretical simulation of the M-H and R-H loops of the SAF-pinned spin valves is compared with these experimental results. Interlayer exchange energies for the SAF obtained from experimental measurements for the various structures were used in the theoretical simulations to improve the fit and optimize the structure. The thermal stability of various SAF structures and the corresponding SAF-pinned spin valves have also been studied and compared with those of AF+SAF-pinned and hard magnet-pinned spin valves reported on previously.1 Structural characterization of the layers and interfaces have been carried out by high-resolution transmission electron microscopy (HRTEM). Three-dimensional atomic scale characterization of the interdiffusion between layers has been conducted using a Local Electrode Atom Probe (LEAP).
1 "A Novel Scheme for Pinning Magnetic Layers in Current Perpendicular to the Plane Spin Valve Devices", C. Papusoi, Z. Tadisina, S. Gupta, H. Fujiwara, G.J. Mankey, and P. LeClair, presented at 53rd AVS International Symposium, San Francisco, CA, November 12-17 (2006).