Magnetic-field-dependent microstructure evolution and magnetic properties of Tb0.27Dy0.73Fe1.95 alloy during solidification

We report on the influence of magnetic field strength on the alloy Tb0.27Dy0.73Fe1.95 during slow-cooling solidification. We examined the effect of magnetic field strength on microstructure, magnetization, and magnetostrictive properties of this giant magnetostrictive alloy. We found that after field-treated solidification, the microstructure of specimens had a distinct grain arrangement and displayed magnetic anisotropy. The crystal orientation changed from random in the field-free treatment to aligned along the 〈110〉 direction in flux densities of 1 and 2.2 T, and along the easy magnetization axis 〈111〉 at a flux density of 4.4 T. In consequence, the magnetostrictive coefficient of the samples under various stresses improved with increasing magnetic flux density. Both the d33 and k33 values and the energy transformation efficiency of the field-treated specimens showed strong enhancements. - Highlights: • We investigate effect of magnetic field on microstructure and properties of Tb0.27Dy0.73Fe1.95. • The alloy shows grain arrangement and magnetic anisotropy in high magnetic fields. • The crystal orientation shows a transformation of random-<110>-<111> with increasing B. • The magnetostrictive coefficient at 10MP improves with increasing B. • The d33 and k33 values suggest the "jump" effect with magnetic fields