Magnetic and Transport Properties of Transition Metal Doped Polycrystalline In O

Synthesis and characterization of transition metal (TM)-doped In ₂O₃ oxide is reported. Most of the samples were found to be paramagnetic, and only Fe and Cr co-doped sample showed as light trace of ferromagnetism at 300 K with saturation magnetization M _s= 0.35 emug/g. Measured transport properties revealed significant differences in transport among the samples. The absolute value of electrical resistivity for the In_1.8Fe_0.1Mn_0.1O₃ sample at 300 K was rho=9.4times10³ Omega middot cm, while In _1.8Fe_0.1Cr_0.1O₃ had rho=62 Omega middot cm at the same temperature. Furthermore, magnetoresistance (MR) studies of In_1.8Fe_0.1Cr_0.1O₃ showed that the sign of MR changes from negative (200 K), with MR_(200K) =-0.2%, to positive T< 50 K reaching maximum absolute value at 10 K, i.e., MR_(10K)=5.2%