Spinell 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.