Magnetic properties and microstructures of perpendicular anisotropy (SmCo7/Cu)n films

Pseudobinary SmCo_7 − xCu_x intermetallic compound films with a TbCu₇-type structure were prepared by sputtered (SmCo₇/Cu)_n multilayer. After annealing, the spacer layer Cu (0.5-1.5 nm) diffused into the SmCo₇ matrix and stabilized the SmCo₇ meta-stable phase. The resulting microstructure was investigated by transmission electron microscopy. Perpendicular anisotropy was obtained by introducing a Cu/Ti dual underlayer during sputtering, resulting in prefer-orientated SmCo₇ (00L) X-ray diffraction peaks. This study observes a maze-like domain pattern in perpendicular anisotropy films and finds single- and multi-domain particles in correlated AFM and MFM images.