Electromagnetic properties of lanthanum manganese oxides doped with iron

The mechanism of GMR effects in La(Mn1-xFex)O-3 (x=0, 0.01, 0.03) oxides has been investigated by means of magnetic measurements, resistivity measurements in magnetic field and Mossbauer spectroscopy. For the x=0.01 sample, the GMR behavior is similar to that of the conventional (La, A)MnO3 (A: divalent cations) oxides. For the x=0.03 sample, even though the temperature dependence of the Mossbauer spectra was similar to that of the x=0.01 sample, the mechanism for the occurrence of the GMR effect seems to be different. The x=0 sample shows a similar behavior to the x=0.03 sample. A thermal stabilization of spin fluctuation is proposed for the x=0 and x=0.03 sample.