Periodical structure and coercive force of sintered RCo5 magnets

The SmCo5 and Smsub(0.5)Prsub(0.5)Cosub(5) sintered magnets structure has been researched through the electron microscopy method of the shadowed carbon replicas. The periodic structure with the periodicity directions along the diagonal axes of the hexagonal unit cell have been detected in the grain basal planes. The structure period grew, when the cooling velocity fell down from 900 deg C and after holding at 750 deg C. Following the 100 degree-per-minute cooling from 900 deg C of the Smsub(0.5)Prsub(O.5)Csub(0.5) optimally sintered magnet, the structure period constituted about 300 A. The formation of the periodic structure is conducive to the lowering the magnets coercive force