Magnetic force microscopy study of magnetically annealed Tb0.36Dy0.64(Fe0.85Co0.15)2 polycrystals

Magnetic force microscopy (MFM) is used to study the domain structures on both transverse and longitudinal sections of Tb0.36Dy0.64(Fe0.85Co0.15)2 ⟨110⟩ oriented polycrystals, which were annealed in a magnetic field of 0.3 T. Different MFM patterns were observed after either perpendicular or parallel field annealing, suggesting that the magnetization of each domain rotates when cooling through their Curie temperature. The long axes of most domains tend to align parallel to the annealing field direction. It gives direct evidence to show the change in the initial magnetic states induced by field annealing, which should be responsible for the variation in the magnetoelastic properties.