Tb-Fe-Co giant magnetostrictive thin film and its application to force sensor

A giant magnetostrictive material (GMM) has large magnetostriction. Therefore, GMM is successfully applied to many actuators and sensors. Recently, practical micro-actuators and micro-sensors have been anticipated in the industry. In this study, the influence of Co addition to a Tb-Fe GMM thin film and the influence of heat treatment were examined. Then the GMM thin film was applied to a force sensor. This paper describes the following: (1) The thin film which made the ratio of cobalt for the sum of iron and cobalt to be 25.5%, and annealing at 300 °C, showed the magnetostriction of 1200 ppm at 80 kA/m. (2) The characteristic of the force sensor that used the GMM thin film with a relative permeability of 210 is examined.