| AVS 57th International Symposium & Exhibition | |
| Magnetic Interfaces and Nanostructures | Thursday Sessions |
| Session MI+TF-ThM |
| Session: | Magnetic Nanostructures, Thin Films and Heterostructures |
| Presenter: | K.B. Karuppanan, University of Texas at El Paso |
| Authors: | K.B. Karuppanan, University of Texas at El Paso M. Garimalla, IIT Madras, India C.V. Ramana, University of Texas at El Paso |
| Correspondent: | Click to Email |
Nickel ferrite is one of the most versatile and technologically important ferrite materials because of its high Curie temperature, high saturation magnetization, low conductivity and thus lower eddy current losses, high electrochemical stability, catalytic behavior. The focus of the present work was to grow Ni.Fe2O3 and NiO.Fe1.925Sm0.075O3 thin films by RF magnetron sputtering and study their structural and electrical properties. Ni.Fe2O3 and NiO.Fe1.925Sm0.075O3 films were grown by sputtering the bulk NiO.Fe2O3 and NiO.Fe1.925Sm0.075O3 targets prepared by solid state chemical reaction. The results indicate that the as-grown films were amorphous. Samples annealed at 1073 K were crystalline. DC electrical conductivity measurements performed in the temperature range 60-300 K indicate the insulating behavior of the materials. The room-temperature conductivity of the NiO.Fe1.925Sm0.075O3 film is less than that of pure Ni ferrite film. Analysis of the conductivity indicates that the small polaron and variable-range-hopping (VRH) mechanisms are operative in 180–300 K and 60–180 K temperature regions, respectively. Frequency variation of the electrical resistivity measurements in the range 1 kHz - 13 MHz indicate that the resistivity decreases with increasing frequency. The mean relaxation time and spreading factor values were found to be larger for the NiO.Fe1.925Sm0.075O3 film which could be due to the fact that larger Sm3+ ion leads to increased bond distance.