Inst. of Mater. Sci. & Eng., National Taiwan Univ.Chou, C.Y.C.Y.ChouKuo, P.C.P.C.KuoYao, Y.D.Y.D.YaoHuang, C.H.C.H.HuangJENG-WEI CHENSun, A.C.A.C.SunFang, Y.H.Y.H.Fang2007-04-192018-06-282007-04-192018-06-282005-0400189464http://ntur.lib.ntu.edu.tw//handle/246246/2007041910042776https://www.scopus.com/inward/record.uri?eid=2-s2.0-27744459124&doi=10.1109%2fTMAG.2005.854821&partnerID=40&md5=82d71abbb526b10dd3e7cc628b763feeThe Fe3O4 powder was mixed with Cu-ferrite powder then sintered in an argon atmosphere at temperatures between 1000°C and 1250°C for 4 h. The Cu-ferrite content in the mixture powder was between 0 mol% and 30 mol%. The effects of Cu-ferrite content and sintering temperature on the magnetoresistance (MR) and microstructure of the sintered ferrite were investigated. It was found that the Cu ions were dispersed uniformly in all sintered samples by the analysis of Cu element mapping of the scanning electron microscopy. The maximum MR ratio of the sintered ferrite at room temperature is about 7.3% when Cu-ferrite content was 7.28 mol% and sintering temperature was 1200°C. From the plot of log ρ versus T-1/2 curves and the measurement of the current versus voltage curves of the sintered samples, it can be known that the magnetoresistance mechanisms in these sintered samples are the contribution of spin-polarized tunneling effect. © 2005 IEEE.application/pdf193119 bytesapplication/pdfen-USCu-ferrite; Magnetoresistance (MR); Spin-dependent tunnelingDispersions; Ferrites; Magnetoresistance; Microstructure; Mixtures; Powder metals; Scanning electron microscopy; Sintering; Cu-ferrite; Sintered ferrite; Spin polarization; Spin-dependent tunneling; Iron compoundsjournal article10.1109/TMAG.2005.8548212-s2.0-27744459124http://ntur.lib.ntu.edu.tw/bitstream/246246/2007041910042776/1/01464159.pdf