MAGNETIZATION, YOUNGS MODULI, AND MAGNETOSTRICTION OF RARE-EARTH-IRONEUTECTIC ALLOYS WITH R=TB0.6DY0.4

Rare-earth-iron alloys, R(0.9)Fe(0.1), R(0.72)Fe(0.28), and R(0.42)Fe( 0.58) (R=Tb0.6DY0.4, containing the R/RFe(2) eutectic composition were prepared by Bridgman and free-standing zone-melting techniques. Magne tization measurements were made in fields up to 800 kA/m between 55 an d 300 K. A huge increase in magnetization below 210 K occurs as the R component becomes ordered. At low applied magnetic fields there is dea r identification of both the ferromagnetic ordering temperature T-C an d the Neel spiral ordering temperature T-N Of R. (For Tb0.6Dy0.4 T-C=1 65 K, T-N=210 K.) Magnetization and magnetostriction measurements reve al very large magnetocrystalline anisotropies for both the R and the R Fe(2) components. Unexpectedly, at 77 K, were the rare-earth component of the eutectic system is ordered and the magnetostriction is large ( lambda(h gamma)>0.6%), th, magnetostriction is largest in the samples containing the largest amount of the RFe(2) phase. Young's modulus mea surements reveal the reduction in the stiffness with the addition of t he softer rare earth to the stiff RFe(2) compound.