Magnetic and electric properties of spinel oxide CoV2O4 (001) films

Abstract

Abstract The epitaxial film growth of CoV2O4 (CVO) on a MgO (001) substrate was successfully achieved using a reactive co-sputtering technique. To explore the conductive CVO films at RT, we grew the films under various conditions, including oxygen-gas flow rates and input radio-frequency power for each target. The Néel temperature of the film was approximately 160 K, which is consistent with previously reported values for bulk CVO. The film was found to be conductive over a wide temperature range and exhibited a negative resistivity temperature coefficient. The mechanism governing the temperature-dependent resistivity of the film can be explained using the one-dimensional variable range-hopping model, at least for temperatures higher than the Néel temperature. The CVO films exhibited a lattice constant close to that of spinel ferrites; therefore, they can be used as conductive buffer layers for electrodes in spintronic applications.