Crystal orientation induced by high magnetic fields during peritectic reaction of alloys

Abstract

Using Tb0.27Dy0.73Fe1.95 as a model alloy, we generate (Tb, Dy)Fe2 and (Tb, Dy)Fe3 phases with preferred orientations. We study the mechanism that determines the preferred crystal orientation of a peritectic alloy under high magnetic fields. Adjusting the preparation parameters yields four Tb0.27Dy0.73Fe1.95 alloys with respective 〈110〉, 〈111〉, 〈112〉, and 〈113〉 directions of the peritectic (Tb, Dy)Fe2 phase parallel to the high magnetic field. The 〈112¯0〉, 〈0001〉, 〈101¯0〉, and 〈101¯3¯〉 directions of the corresponding primary (Tb, Dy)Fe3 phase are parallel to the magnetic field. We deduce the orientation relationships (1¯11)//(0001) and [110]//[112¯0] for the (Tb, Dy)Fe3 and (Tb, Dy)Fe2 phases. The growth velocity and high magnetic field do not change the orientation relationships of these two phases. The high magnetic field induces the rotation of the primary (Tb, Dy)Fe3 phase and then affects the orientation of the peritectic (Tb, Dy)Fe2 phase. Magnetic torque induces stacking of the {0001} plane perpendicular to the magnetic field, meaning the c-axis of the primary (Tb, Dy)Fe3 phase aligns parallel to the field. At this time, the {111} plane of the (Tb, Dy)Fe2 phase grows perpendicular to the magnetic field, as reflected in the preferred orientation of the (Tb, Dy)Fe2 phase along the 〈111〉 direction.