Magnetization processes and magnetostriction of Tb0.27Dy0.73Fe2 single crystal along 〈110〉 direction

Abstract

The magnetostriction and magnetization process of a twin-free Tb0.27Dy0.73Fe2 single crystal along the 〈110〉 direction has been studied by strain gauge, vibrating sample magnetometer, and domain observation techniques. It was observed that the magnetostriction of the sample remained unchanged with increasing magnetic fields when H<1 kOe and quickly increased in the range 1<H<7.5 kOe. No “jump” effect was observed during the magnetization process and the magnetostrictive hysteresis was large when H<2.5 kOe. Observations by the Bitter colloid technique at room temperature revealed curved domain walls which became straight at higher and lower temperatures in {100} and {111}, respectively, indicating the transition to different 180° walls for H<1 kOe. The domain patterns were clearest on a {100} surface. Above the spin reorientation temperature, 109° and 71° wall motions dominated the magnetization process in the range 1.5 kOe<H<4 kOe, but below it, clear 90° wall motions were observed. Little change in the magnetized domain pattern was observed at different temperatures suggesting that many domain walls occupy the same planes. Similar room temperature patterns were observed at remanence with an applied stress along 〈111〉 in excess of 5 MPa. These results are consistent with theoretical magnetomechanical behavior based on a 〈1uu〉, 0<u<1, transition in easy direction.

The effect of magnetic annealing on the magnetostriction for Sm-Dy-Fe rod alloys

“…12 In fact, the initial moments of the magnetostrictive alloys will be redistributed during the magnetic annealing and the redistribution of the initial moments may improve the magnetostriction of alloys. 11,13 The result in Fig. 5 has shown that the redistribution of the initial moments is dependent on the magnetic annealing temperature and the magnetic annealing at the temperature of 543 K leads to the favor of the redistribution of the initial moments along the direction perpendicular to the rod axis, resulting in the distinct increase of the magnetostriction value.…”

Dynamic magnetoelastic properties of TbxHo0.9−xNd0.1(Fe0.8Co0.2)1.93/epoxy composites

“…2, d 33 keeps the small value at a relatively low field due to the more active movement of 180°domain wall, and then it increases with increasing H bias , which can be ascribed to the increase in magnetostriction contributed by the non-180°domain wall motion. d 33 displays a maximum value at a critical field around H bias ∼ 100 kA/m, corresponding to the domination of non-180°domains in the technical magnetization process [19,20]. Thus, it would be not difficult to understand these behaviors for the H bias dependence of d 33 , considering the fact that the non-180°domain wall motion gives rise to the changes in magnetization with an accompanying magnetostriction, while the 180°domain wall motion only affects the magnetization [19].…”

Structure, magnetic properties and magnetostriction of Fe81Ga19 thin films

“…The magnetostriction and magnetization process of Dy 0.7 Tb 0.3 Fe 2 alloy have been investigated [1,2]. Recently, it is found that single crystal /1 0 0S-oriented Fe 81 Ga 19 alloy exhibits a giant magnetostriction approaching 400 ppm with low saturating magnetic fields of several hundred Oersteds and also displays a limited temperature dependence over a À20 to 80 1C range [3][4][5].…”