Enhancement of magnetic anisotropy of nanocrystalline FeTaN films by Ti underlayers and magnetic field annealing

Evolution of magnetic anisotropy in a FeTaN film was investigated as a function of annealing temperature, induction of magnetic field, and the addition of a Ti underlayer. The Fe78.8Ta8.5N12.7 films studied in this work are deposited as amorphous, and their soft magnetic properties evolve through the crystallization during postdeposition annealing. The films show a strong isotropy at all annealing temperatures with and without magnetic field induction. Employment of a Ti underlayer greatly enhances the uniaxial anisotropy when combined with a magnetic field annealing. The enhanced anisotropy leads to a significant improvement of high frequency response through an increased ferromagnetic resonance frequency.