Magnetostriction of Tb–Dy–Fe crystals

〈111〉-oriented twin free Tb–Dy–Fe single crystals, 〈112〉- and 〈110〉-oriented twinned “single” Tb–Dy–Fe crystals were prepared using floating zone melting technique. Magnetostrictive performances of the crystals were investigated. Better low-field properties were observed in the 〈110〉 twinned crystals than in the 〈112〉 crystals. The highest properties were achieved in the 〈111〉 twin free single crystals. Even though there are still oxidized particles in the present 〈111〉 single crystals, a large magnetostrictive jump of 1700 ppm and a very low saturation magnetic field of 500 Oe were obtained. To understand magnetization and magnetostriction of different Tb–Dy–Fe crystals, theoretical modeling was carried out based on a simplified domain rotation model. Magnetization moment rotation paths of different domains were simulated and hence the resultant magnetostriction was obtained, which can well account for the experimental results of different crystals. The limitation of the domain rotation model was also discussed.