V2O3(0001) surface termination: phase equilibrium.

Complementary but independent medium-energy and low-energy ion scattering studies of the (0001) surfaces of V(2)O(3) films grown on Pd(111), Au(111) and Cu(3)Au(100) reveal a reconstructed full O(3)-layer termination creating a VO(2) surface trilayer. This structure is fully consistent with previous calculations based on thermodynamic equilibrium at the surface during growth, but contrasts with previous suggestions that the surface termination comprises a complete monolayer of vanadyl (V=O) species.