Magnetoresistance and microstructure of the sintered ferrite of the mixture of Fe_3O_4 and Co-ferrite powder

摘要

The Fe3O4 powder was mixed with Co-ferrite powder then sintering in argon atmosphere at temperatures between 1000°C and 1250°C for 4 hours. Effects of the sintering temperature, microstructure and Co-ferrite content on the magnetoresistance of the sintered ferrite of the mixture powder were investigated. The Co-ferrite content in the sintered ferrite was between 0 mol% and 32.28 mol%. It was found that the Co ions were dispersed uniformly in all sintered samples by the analysis of Co element mapping of the scanning electron microscopy. The maximum magnetoresistance ratio at room temperature is about 7.45% when Co-ferrite content was 4.26 mol% and sintering temperature was 1200°C.