Soft magnetism of high-nitrogen-concentration FeTaN films

Abstract

High-nitrogen-concentration FeTaN films have been newly developed as a high performance magnetic head core material. 10.5–14.5 (at. %) N, 8–13 Ta, and balance Fe composition films, prepared by a nitrogen reactive sputtering method followed by appropriate annealing (500–550 °C), have high saturation flux density (14–17 kG) and excellent soft magnetic properties: such as low coercivity (∼0.1 Oe), high relative permeability (3000 at 20 MHz), and small saturation magnetostriction ( < 0.5 × 10−6). Fine crystal structure is one of the most essential origins for the soft magnetism of FeTaN films. The FeTaN films are expected to realize recording density increases and rubbing noise reduction with high durability and high reliability due to their high Vickers hardness (1000) and their higher corrosion resistance than Sendust film.