Abstract A systematic investigation has been carried out on effect of Cr-doping on structural, magneto-resistance, magnetic and thermoelectric power properties of La0.65Ca0.35Mn1-xCrxO3 compounds. Samples were prepared using conventional solid state reaction method. The XRD analysis using Rietveld refinement reveals that the samples are single phased. Temperature dependent electrical resistivity measurements show the existence of the expected metal-insulator transition (TMI) which is followed by a small hump at temperatures lower than TMI. With the application of magnetic field, resistivity of all the samples is found to decrease and TMI is observed to shift towards higher temperature. This is attributed to induced magnetic ordering of the localized t2g spins and increased electron transfer integral between Mn3+/Mn4+ via oxygen by the application of magnetic field. MR% is observed to increase with the increasing Cr concentration. Magnetic studies show that the Curie temperature, TC and magnetic moment decreases with Cr-content which is consistent with the electrical studies. Electrical resistivity and thermoelectric power data have been analyzed using theoretical models and both suggest that the small polaron hopping (SPH) model is operative in the high temperature insulating region for the entire series of samples.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering