Magnetostriction of Tb0.36Dy0.64(Fe1−xCox)2 (x = 0–0.20) 〈1 1 2〉-oriented crystals

〈1 1 2〉-Oriented crystals of the highly magnetostrictive alloys Tb0.36Dy0.64(Fe1−xCox)2 (x = 0–0.20) and Tb0.3Dy0.7Fe2 have been prepared by zone melting directional solidification method with growth velocities of 240 and 600 mm/h. It is found that 〈1 1 2〉-oriented crystals were formed with dendritic-solidified morphologies. Narrower lamellar spacing is observed in samples obtained with higher growth velocity. Magnetostrictive properties were measured under various compressive pre-stresses at room temperature (20 °C), elevated temperature (100 °C) and cryogenic temperature (−80 °C). Magnetostriction “jump” effect is less obvious in all Tb0.36Dy0.64(Fe1−xCox)2 〈1 1 2〉-oriented crystals at −80 °C than at 20 and 100 °C. The measurement results reveal that large magnetostriction in the 〈1 1 2〉-oriented polycrystalline materials of Tb0.36Dy0.64(Fe1−xCox)2 can be retained in a wide temperature range from −80 to 100 °C.