Magnetostriction in FeTaN thin films

Magnetostriction is studied in FeTaN single layer thin films deposited by high power density, high growth rate, DC magnetron sputtering. Magnetostriction is found to increase linearly with the nitrogen content of the films, passing from negative to positive with increasing nitrogen content. Thinner films exhibit larger positive magnetostriction than thicker films deposited at the same nitrogen flow rate. Film stress is found to be tensile in as-deposited films grown at zero nitrogen pressure. As the nitrogen content in the films increases, the film stress changes from tensile to compressive and increases in magnitude, while annealing at 300°C reduces the magnitude of film stress without affecting magnetostriction. Stress anisotropy is found to reach a minimum at low nitrogen flow rate, and stripe domain formation accompanies large stress anisotropy at high nitrogen flow rates