摘要
The effects of heat treatment conditions on the magnetic properties and microstructure of M-type strontium ferrite according to calcination temperature were analyzed.Strontium ferrite Sr0.06Ca0.52La0.52Fe11.68Co0.22O19magnetic powder was prepared by a standard ceramic process.During experiments,the calcination temperature was varied from 1180 to 1260℃,and sintering temperature was fixed.While the M-phase(SrFe12O19)existed with hematite(Fe2 O3)in the powder calcined at below 1220℃,the pure M-phase was observed in the powder calcined at over1240℃.With an increase in the calcination temperature,the magnetization of the calcined powder increases,meanwhile,the coercivity decreases.The magnetization is improved by decreasing the lattice constant c and activating the Fe3+-OFe3+superexchange interaction,and the coercivity decreases by the large particle sizes due to the grain growth.
The effects of heat treatment conditions on the magnetic properties and microstructure of M-type strontium ferrite according to calcination temperature were analyzed.Strontium ferrite Sr0.06Ca0.52La0.52Fe11.68Co0.22O19magnetic powder was prepared by a standard ceramic process.During experiments,the calcination temperature was varied from 1180 to 1260℃,and sintering temperature was fixed.While the M-phase(SrFe12O19) existed with hematite（Fe2 O3） in the powder calcined at below 1220℃,the pure M-phase was observed in the powder calcined at over1240℃.With an increase in the calcination temperature,the magnetization of the calcined powder increases,meanwhile,the coercivity decreases.The magnetization is improved by decreasing the lattice constant c and activating the Fe3+-OFe3+superexchange interaction,and the coercivity decreases by the large particle sizes due to the grain growth.
