Magnetostriction of single crystal and polycrystal rare earth-Fe2 compounds

Magnetostriction measurements on single-crystal and polycrystal TbFe2 and ErFe2 are reported and compared. For TbFe2 the largest known room temperature magnetostriction constant was found: lambda111 = 2400 x 10-6. For ErFe2: lambda111 = -300 x 10-6; lambda111 is the dominant magnetostriction constant and the major source of the magnetostriction of the polycrystalline rare earth--Fe2 alloys. TbFe2 possesses the largest known cubic anisotropy constant. At room temperature K1 = -7.6 x 107 erg/cm3. The sign of the anisotropy plays an important role in determining the field dependence of the polycrystalline magnetostriction