Magnetostriction of (Fe-Co)3 Tb Compounds and Amorphous Fe3 Tb Alloys

The magnetostriction of (Fe1-x Cox) Tb (0¿×¿1.0) compounds and amorphous Fe3Tb alloys were measured at room temperature and at 77K. The value of ¿¿-¿¿ at 77K and 20 kOe of (Fe1-xCox)3Tb compounds increases drastically from 1500×10^¿6 to 3000×10^¿6 as x is increased from 0 to 1.0. The value of ¿¿-¿¿ for amorphous Fe3Tb is about 30 to 40% smaller than the value for the crystalline material. The effect of Co substitution on the magnetostriction of (Fe1-xCox)Tb compounds is discussed on the basis of the single ion model. The magnetic field dependence of magnetostriction in Fe3Tb amorphous alloy is also discussed in connection with the magnetization process.