Structure and electrical properties of Fe–Mn–Co–O spinel

Abstract

Sub micro-sized Fe0.1Mn1.45Co1.45O4 powders were obtained using the sol–gel method with EDTA as a complexing agent. The sinters obtained from these powders were characterized by means of scanning electron microscopy, X-ray fluorescence, the Mössbauer spectroscopy, X-ray diffraction, and the 2-probe 4-point direct current method. The X-ray diffraction investigation of the sinter revealed that only the cubic phase had formed. Scanning electron microscopy showed that the sample was dense and exhibited a certain porosity. The addition of iron ions to the Mn1.5Co1.5O4 spinel reduced the electrical conductivity of the obtained sinter from ca. 60 to over 50 S/cm at 973 K. The Mössbauer studies showed the full incorporation of iron into the lattice structure of Mn1.5Co1.5O4. In conclusion, the iron-doped spinel appears to be suitable for the surface modification of ferritic stainless steel substrates used in solid oxide fuel cells interconnects.