Rare earth-iron compounds for actuators and sensors

With their individual magnetoelastic properties, particular crystalline compounds and amorphous alloys are frequently referred to as actuator and sensor materials respectively. Both types of material are often referred to as `magnetostrictive´ but it is only the former which develops large magnetostrictive strains, the latter being better known for their superior stress sensitivity. The present paper is concerned with the essential properties of each kind, their limitations as transducer materials and the present state of research and development that is directed towards the improvement of magnetostrictive transducer materials for a wider range of applications