Preparation and characterisation of iron substituted Mn_1.7Cu_1.3-xFe_xO₄ spinel oxides (x = 0, 0.1, 0.3, 0.5)

Spinel oxides with the general formula Mn_1.7Cu_1.3-xFe_xO₄ (x= 0, 0.1, 0.3, 0.5) were prepared and evaluated in this work for their properties at high temperatures. The effect of partially substituting Cu by Fe has not been studied so far for this group of materials and is thus evaluated in this work. Mn_1.7Cu_1.3-xFe_xO₄ powders were synthesised by a soft chemistry process and studied in terms of crystallographic phase analysis, electrical conductivity, thermal expansion, and sinterability behaviour. The results show that the Fe content has a significant influence on the phase composition and the resulting properties. Characterisation of the dilatometry and conductivity coupled with XRD phase analysis across a wide temperature range allowed the relations between the materials properties and compositions to be observed. The results indicate that Mn_1.7Cu_0.8Fe_0.5O₄ is a promising material for use as a protective coating for interconnects in intermediate temperature Solid Oxide Fuel Cells.