Microstructure and domain structures of Sm0.56GdxDy0.44-x(Co0.68Fe0.22Cu0.08Zr0.02)(7.22) magnets with low temperature coefficients

The microstructure and domain structures of high performance temperature-co mpensated sintered magnets with composition of Sm0.56GdxDy0.44-x(TM)(7.22) (TM=Co0.68Fe0.22Cu0.08Zr0.02)(7.22) (0.0 less than or equal to x less than or equal to 0.4) have been investigated by using electron microscopy and ma gnetic force microscopy. Both microstructure and magnetic properties of the se magnets show a significant dependence on the content of heavy rare earth Gd and Dy. The intrinsic coercive force increases significantly with incre asing Gd content. It is found that there are two different types of grains in the magnets, which show different domain structures. The larger magnetoc rystalline anisotropy, larger cell size, and coarser grain boundary region give rise to a higher coercivity in the Gd-rich magnets. (C) 1999 American Institute of Physics. [S0021-8979(99)06114-9].