Possible structures of nonstoichiometric tin oxide: the composition Sn2O3

Structural aspects of crystalline tin oxide and its interfaces with composition Sn2O3 are considered computationally based on first principles density functional calculations. The possibility of formation of different nonstoichiometric tin oxide crystals and SnO2/SnO interfaces is shown. The lowest total energy per Sn2O3 unit was evaluated for a layered Sn2O3 crystal, where oxygen vacancies are arranged into the (101) plane in a rutile structure system. Interface structures with orientations SnO2(101)/SnO(001) and SnO2(100)/SnO(100), corresponding to composition Sn2O3 are only slightly less stable. Their estimated interface energies are 0.15 J m(-2) and 0.8 J m(-2), respectively. All geometries have components similar to well-known rutile structure SnO2 and litharge structure SnO geometries. Most stable Sn2O3 crystals include SnO6 octahedra similar to those found in rutile structure SnO2.