High Coercive NdFeB Thin Film Obtained by Diffusion Annealing

The magnetic properties and microstructure of diffusion annealed Ta/Nd/NdFeB/Nd/Ta] thin films have been investigated. The films were deposited on Si substrate with various thickness ratio of Nd/NdFeB layer (R=0 similar to 3.3), then diffused and crystallized by annealing at 650 degrees C for 10 min. The film without Nd layer showed soft magnetic behavior and high content of alpha-Fe phase. The films with R greater than or equal to 1 showed good hard magnetic properties with the high coercivity of about 20 kOe.