Domain wall pinning in high temperature SM(Co, Fe, Cu, Zr)7-8 magnets

A finite element method was used to simulate domain wall pinning in SmCo5/Sm2Co17 based permanent magnets. The finite element model was built according to the cellular microstructure obtained from transmission electron microscopy investigations. The numerical results show a strong influence of the dimension of the cell boundary phase on the coercive field, which significantly increases with the extension of the 1:5/7-type cell boundary phase. The calculated values of the coercive field are in the range from 1000 to 2000 kA/m assuming a cell size varying from 80 to 160 nm. The difference of the magnetocrystalline anisotropy between cell boundary and cell interior phases is determined by the Cu content of the magnet. (C) 2000 American Institute of Physics. [S0021-8979(00)63808-2].