Solid solution of epitaxially grown (Sr, Mg)TiO3 thin films

Microstructures of (Sr1-xMgx)TiO3 thin films epitaxially frown on (001) SrTiO3 substrates were investigated by X-ray diffraction and high-resolution transmission electron microscopy to discuss the solid-solution of the SrTiO3-MgTiO3 system under pulsed laser deposition processes. In cases of x = 0.15 and x = 0.3, magnesium ions were mostly accommodated at A-sites of the perovskite structure of general formula ABO(3), to form single-phase perovskite thin films without ilmenite secondary phases, and the possibility of partial B-site occupation of magnesium ions was inferred to interpret the formation of (100) and (010) planar defects with a crystallographic shear structure. The (Sr0.5Mg0.5)TiO3 thin film exhibits a phase-separated microstructure consisting of an epitaxial crystalline perovskite phase and an amorphous phase, which could be derived from the limitation of the magnesium solubility in the SrTiO3 perovskite lattice.