High temperature magnetostriction of TbFe2and Tb.27Dy.73Fe2

The RFe2alloys (R=Tb,Dy,Sm) offer opportunities for achieving very high magnetostrictions at temperatures far above room temperature. Saturation strains greater than 1000 ppm have been measured at temperatures as high as 200°C. In addition to saturation strain measurements, we have measured magnetostriction of Tb.27DY.73Fe2under compressive stress from -30°C to 80°C, a temperature range encountered in many magnetomechanical transducers. From these data optimum magnetic and mechanical biases can be determined. These measurements give an insight into the magnetization process in three distinct regions: (1) high cubic [100] easy anisotropy, (2) low anisotropy and (3) high cubic [111] easy anisotropy.