S.C.، Chen, نويسنده , , C.T.، Lie, نويسنده , , P.C.، Kuo, نويسنده , , A.C.، Sun, نويسنده , , C.Y.، Chou, نويسنده , , I.J.، Chang, نويسنده , , T.H.، Wu, نويسنده , , J.W.، Chen, نويسنده ,
Fe/sub 3/O/sub 4/ powder was mixed with MgO powder and then sintered in an atmosphere of argon at various temperatures for 3 h to form Mg-doped Fe/sub 3/O/sub 4/ ferrites. The effects of the sintering temperature, microstructure, and Mg content on the magnetoresistance of sintered Fe/sub 3/O/sub 4/ ferrites were investigated. X-ray diffraction and chemical titration analysis of Fe/sup 2+/ and Fe/sup 3+/ ions indicate that the nonstoichiometric phases of Fe/sub 3/O/sub 4+X/ and MgFe/sub 2/O/sub 4-x/ coexisted in the sintered sample. The temperature dependence of resistivity was examined. A plot of log (rho) against T/sup -1/2/ of the sintered samples exhibits a linear relationship, indicating that the dominant magnetoresistance effect is spin-dependent tunneling. The maximum magnetoresistance of the sintered sample is about 7.3% at room temperature at a magnetic field of 12 kOe. The Mg content of this sample is 0.93 at.%.
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