Magnetoelastic transition and giant anisotropic magnetostriction effect in textured Mn<sub>1.9</sub>Co<sub>0.1</sub>Sb polycrystal

Abstract

Mn2Sb-based alloys have extremely promising practical applications in many fields owing to their abundant and controllable magnetofuntional properties around the first-order magnetoelastic transition, as well as their low costs. However, only a few studies on the magnetostrain of these alloys have been reported. Herein, a highly textured Mn1.9Co0.1Sb polycrystal is fabricated by using the arc-melting technique, which produces a strong temperature gradient induced by rapid cooling during the arc-melting process, resulting in the highly selective orientation of crystal growth. X-ray diffraction and thermomagnetic measurements show that the grains grow in certain crystallographic directions. Metamagnetic transition is revealed by the isothermal magnetization curve measurements, which is observed to be more obvious at lower temperatures. The standard resistive strain-gauge method is adopted to measure the magnetostriction effect. Giant anisotropic magnetostrain values of up to 0.246% and −0.11% are obtained parallel and vertical to the texture of the alloy, respectively. This magnetostriction effect mainly originates from the anisotropic lattice distortion across the first-order magnetoelastic phase transition.