Linear-Drive Type Modulated Rotating Magnetic Field and Three Dimensional Crystal Orientation

Abstract

Modulated rotating magnetic field (MRF) enables bi-axial grain alignment of substances with tri-axial magnetic anisotropy. This is a candidate of material production process which can be applicable at room temperature. However, rotation of magnetic flux is inappropriate for continuous production process with linear motion. The author introduce two topics in this review article. One is requirements for alignment of the hard magnetization axis by a rotating magnetic field. The other is development of an equipment that can generate a linear-drive type MRF. In the former topic, the author describes that magnetic energy for orientation and rotation speed of magnetic flux should be taken into account for achieving the alignment of the hard axis with high orientation degrees. In the latter topic, the author describes the details of the equipment including a design of arrayed permanent magnet unit. Moreover, the bi-axial magnetic alignment of practical rare-earth-based cuprate superconductors, DyBa₂Cu₃O_y, with twin microstructures was attempted using the equipment as a proof-of-principle experiment.