MAGNETOSTRICTION OF TB-DY-FE CRYSTALS

[111]-oriented twin free Tb-Dy-Fe single crystals, 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 w ere 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 magn etic field of 500 Oe were obtained. To understand magnetization and ma gnetostriction of different Tb-Dy-Fe crystals, theoretical modeling wa s carried out based on a simplified domain rotation model. Magnetizati on moment rotation paths of different domains were simulated and hence the resultant magnetostriction was obtained, which can well account f or the experimental results of different crystals. The limitation of t he domain rotation model was also discussed. (C) 1998 American Institu te of Physics. [S0021-8979(98)06723-1].