Electrical Conductivity of the Manganese Chromite Spinel Solid Solution

Spinel phase based on Mn 1+ x Cr 2− x O 4 (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.