Magnetic and electrical properties of Mn2CoO4 spinel

In this paper, the structural, microstructural, electrical and magnetic properties of an Mn2CoO4 spinel synthesized by means of EDTA gel processes are reported. The Rietveld refinement analysis of high-temperature X-ray diffraction (HT-XRD) data revealed the formation of a tetragonal Mn2CoO4 phase. This phase undergoes a structural change into a cubic phase at elevated temperatures, and this process is associated with a change in lattice parameters. The afore-mentioned phase transition was also investigated via high-temperature Raman spectroscopy. Temperature-dependent magnetization data revealed changes in the magnetic ordering temperature, which had been caused by the formation of antiferromagnetic (AFM) and ferromagnetic (FM) phases at low temperatures. Electrical conductivity increased with temperature and reached a level of 4.3 S.cm(-1) in air at 1073 K, which indicates that the spinel exhibited semiconducting properties. This oxide can be considered as a material for protective-conducting coatings on ferritic stainless steel used to manufacture interconnects for solid oxide fuel cells.