Electrical Conductivity of the Manganese Chromite Spinel Solid Solution

Spinel phase based on Mn1+xCr2−xO4 (0≤x≤1) was synthesized and characterized. The lattice parameter of the spinel was found to increase with increasing Mn content up to x=0.7. At x>0.7, the cubic spinel changed to tetragonal because of Jahn–Teller distortion. The electrical conductivity of the spinel also increased with increasing Mn content. Electrical conduction in this phase was likely through a small polaron hopping mechanism. The spinel phase showed similar electrical conductivity in both oxidizing and reducing environments expected in a solid oxide fuel cell operation.