Barium ferrite thin films without a dead layer

A barium ferrite layer with low-Ba content was used as an underlayer for a high-Ba content barium ferrite thin film. During the post-deposition annealing, the underlayer which has a lower nucleation rate than the top layer prevented grains from nucleating in the interdiffused region at the interface with the substrate. As a result, the magnetic properties were dramatically improved as indicated by much higher coercivity squareness S* and narrower switching field distribution.