In this work, magnetization reversal mechanisms in various 35 nm diameter Fe 80Ga 20/Cu multilayered nanowire arrays were studied by a vibrating sample magnetometer (VSM) equipped with vector coils, making it possible to monitor both x- and y-components of the sample moment during reversal. When reversal fields were applied in the low angular range (0 60°), all nanowire structures, irrespective of Fe 80Ga 20 or Cu aspect ratios, experienced reversal by nucleation and propagation of a vortex domain wall. However, when fields were applied in the high angular range of 60-90°, reversal occurred by coherent rotation. Using vector-VSM, it was further shown that in structures with pancake-like Fe 80Ga 20 segments, the extent to which moments in adjacent segments rotate cooperatively decreased as the Cu thickness increased.
Bibliographical noteFunding Information:
The authors would like to thank the U.S. Office of Naval Research and Dr. Jan Lindberg (ONR N00014-06-1-0530) for their support. We also acknowledge critical discussions with Dr. Stephanie Hernandez. We are grateful to the National Science Foundation (NSF) for support via their MRSEC and NNIN centers, and the staff of the UMN Characterization Facility and Nanofabrication Center.