We studied the dependence of exchange coupling on cooling-field strength in an exchange-biased spin valve with a synthetic antiferromagnetic layer by experiment and theory. Our theory calculates magnetic anisotropy energies in each magnetic layer composing the spin valve during the field-cooling process, finds the minimum state of total energy, and explains how the magnetizations in the layers interact with one another during field-cooling under various cooling-field strengths. Calculations based on the theory well match results of the experimental measurements. Our observation shows that one has to carefully choose the cooling-field strength optimal for designing exchange-biased spin devices having a synthetic antiferromagnetic layer; otherwise the exchange coupling direction can significantly deviate from the cooling-field direction, which impairs performance.
Bibliographical noteFunding Information:
This research was supported in part by Samsung Electronics Co., Basic Science Research Program (2011-0003263) and Pioneer Research Center Program (2011-000-2116) funded by the Ministry of Education, Science and Technology, and the IT R&D program of MKE/KEIT (KI002189, Technology Development of 30 nm Level High Density Perpendicular STT-MRAM) in Korea.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)