We studied the effects of Pd, Ru, and Ta seed-layers on the perpendicular magnetic properties of Co/Pd multilayers, promising materials for high-density magnetic recording media. Among the various seeds, the Ta seed-layer demonstrated a large coercivity and most highly promoted fcc (111) preferred orientation of the Co/Pd multilayer. We also patterned films into island arrays with sizes of 2 × 2 μm2, 5 × 5 μm2, and 10 × 10 μm2 to investigate the effect of size on the magnetic properties. The coercivity increased as the island size decreased. The 2 × 2 μm2 patterned Co/Pd multilayer with the Ta seed-layer showed a coercivity about six times greater than that of the un-patterned film. This increase can be explained by a change in the magnetization reversal mechanism from domain wall propagation to domain rotation.
Bibliographical noteFunding Information:
The authors thank Prof. Dong Ryeol Lee of Soongsil University and Dr. Jin Woo Kim of the PAL for their help with data analyses of XRD spectra. This research was supported in part by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology ( 2010-0015924 ), by the grant from Center for Nanoscale Mechatronics & Manufacturing, one of the 21st Century Frontier Research Programs ( 2010K000189 ) funded by the Ministry of Education, Science and Technology, Korea, and by the IT R&D program of MKE/KEIT ( KI002189 , Technology Development of 30 nm level High Density Perpendicular STT-MRAM).
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Surfaces and Interfaces
- Surfaces, Coatings and Films
- Metals and Alloys
- Materials Chemistry