Transport Properties of Rare Earth Manganese Oxide Lao.67 Ca0.33Mn1-x FexO3

The transport properties were studied for rare earth manganese oxide La0.67Cao.33Mn1-x FexO3(x=0-O.3) systems. It is found that with increasing Fe^3 -doping content x, the resistance increases and the insulator-metal transition temperature (T1M) shifts to lower temperature. If the doping content is small, the transport properties manifest metallic characteristics in the temperature range of T＜T1M, while they will obey a thermal activation model in the temperature range of T＞T1M. Such a behavior may be attributed to the Fe^3 -doping and possible Mn ions scattering to electrons. The Fe^3 doping may lead to the formation of Fe^3 -O^2- -Mn^4 channels, which could terminate the double exchange Mn^3 -O^2--Mn^4 channels. The antiferromagnetic clusters of Fe ions may induce the Mn ions to scetter to the electrons.