Abstract
Improvements in the magnetic and magnetostrictive properties of amorphous FeB sputtered films were achieved by doping them with rare earth elements (RE = Pr and Tb) were examined in detail for the composition system Fe100-x-yBxREy (x = 15-40 at%, y = 0-3.5 at%). It was found that magnetic softening is promoted by adding a small amount of RE (y = 1 at% for Pr, y = 1.5 at% for Tb), while ensuring that film maintains a relatively high magnetostriction constant. These properties remain almost completely insensitive to thermal annealing at temperatures up to 350°C, suggesting that RE elements with large ion radii act as impurity elements, causally stabilization of the amorphous structure and an increase in the electrical resistivity. The linear change of λ vs. H without any hysteresis loop and the high magnetostrictive sensitivity dλ/dH are very favorable for sensor and/or actuator applications.
