The magnetic domain structures of (Tb0.3Dy0.7)Fe-1.95 alloys were investigated using scanning probe atomic and magnetic force microscopies. Results demonstrate that the specimen surface presented corrugated and spiked domain configurations interpreted in terms of surface closure domains in cubic magnetic materials after the specimen was annealed at 673 K for 2 h in an ultra-high vacuum of 5x10(-5) Pa. However, a thin soft magnetic Fe layer appeared on the specimen surface after annealing at 723 K for 2 h in a relatively high vacuum of 5x10(-3) Pa. As a result, the demagnetized energy in the specimen surface is largely reduced and the interior magnetic domain configurations of the specimen are observed. The results maybe provide an approach for detecting the interior magnetic domain structures of TbDyFe alloys or other cubic magnetic materials.

Keywords: magnetic domain; magnetic force microscopy (MFM); demagnetized energy; TbDyFe