STRUCTURE, MORPHOLOGY, AND MISFIT ACCOMMODATION MECHANISM OF MGIN2O4 FILMS GROWN ON MGO(001) SUBSTRATES BY SOLID-STATE REACTION

Thin MgIn2O4 spinel films were grown on cleaved MgO(001) substrates by a surface reaction between the MgO substrate and an In2O3 vapour at temperatures around 1400-degrees-C. Investigations by SEM, EDX, TEM, SAED, and HREM revealed the films to grow in almost [001] orientation and to develop a specific morphology. They are composed of domains, whose crystal lattices are tilted by about 3-degrees around two different (110) axes. A network of interfacial dislocations with Burgers vectors a/2 [011] and a/2 [101] was found accommodating the large lattice misfit of +4.5%. The observations are discussed in terms of a model featuring the interplay between the atomic mechanism of the solid state reaction, and the properties of the interfacial dislocations persisting at the moving reaction front.