Magnetic Properties and Microstructure of Electrodeposited Co/Cu Multilayers

抄録

Co/Cu multilayers were electrodeposited on a brass substrate with a target layer thickness of 4 nm in a single electrolyte, and their magnetic properties and microstructure were investigated. Cross sections of the samples were observed using field-emission scanning electron microscopy, and electron backscatter diffraction measurements were also conducted. Each sample was composed of columnar crystal grains vertical to the substrate, with each grain having a Co/Cu multilayered structure. During growth of the grains, the layers were bent regularly at specific boundary lines in the cross section and were thus composed of a zigzag multilayered structure. The magnetic properties were measured using a vibrating sample magnetometer. The saturation magnetization and residual magnetization of Co in the sample were close to those for a 500-nm-thick Co layer, whereas the coercivity was significantly larger. The mechanism responsible for this coercivity increase was partly determined to be topological coupling among the Co layers which are single domain and have in-plain magnetic anisotropy.