Magnetostriction and hysteresis of (Tb_0.36Dy_0.64) _1-xHo_xFe_1.95 alloys

The crystal structure, lattice constant, Curie temperatures, spin reorientation temperature, magnetization, magnetocrystalline anisotropy constant and magnetostriction of (Tb_0.36Dy_0.64) _1-xHo_xFe₂ (x=0.1, 0.2, 0.3) alloys were investigated. X-ray diffraction patterns demonstrate all the (Tb _0.36Dy_0.64)_1-xHo_xFe₂ alloys possess MgCu₂-type cubic Laves structure. The Curie temperature T_c of (Tb_0.36Dy_0.64) _1-xHo_xFe_1.95 alloys decreases slightly from 387°C for Tb_0.36Dy_0.64Fe₂ to 379°C for x=0.1, 375°C for x=0.2 and 362°C for x=0.3. The spin reorientation temperature T_r increases from -94.1°C for Tb _0.36Dy_0.64Fe₂ to -57°C for x=0.1 and -51°C for x=0.2. The magnetocrystalline anisotropy coefficient K₁ of (Tb_0.36Dy_0.64)_1-xHo_xFe ₂ alloys decreases with increasing Ho concentration. The magnetostriction of (Tb_0.36Dy_0.64)_1-xHo _xFe_1.95 alloys was examined under applied magnetic field H (0<H<350 mT) in the temperature range from -60°C to 80°C. The (Tb_0.36Dy_0.64)_1-xHo_xFe₂ alloys (x≤0.2) have the character of giant magnetostrictive in a wide operating temperature range from -60°C to 80°C. The hysteresis of magnetostriction versus the applied field was reduced due to the addition of Ho concentration. Small amounts of Ho (x≤0.2) replacing Tb and Dy in the (Tb_0.36Dy_0.64)_1-xHo_xFe₂ formulation provide a much larger decrease in hysteresis losses with relatively small changes of magnetostriction in wide operating temperature range between -60°C and 80°C at magnetic field of 100mT.