In-situ x-ray studies of compositional control during synthesis of LaGaO3 by radio frequency-magnetron sputtering

In-situ synchrotron x-ray scattering has been used to monitor and control the synthesis of LaGaO₃ epitaxial thin films by $90°$ off-axis RF-magnetron sputtering. Films deposited from a single LaGaO₃ source were compared with those prepared by alternating deposition from separate La₂O₃ and Ga₂O₃ sources. The conditions for growth of stoichiometric films were determined by real-time monitoring of secondary phase formation as well as from features in the diffuse scatter from island formation during synthesis. These results provide atomic-scale insight into the mechanisms taking place during reactive epitaxial growth and demonstrate how in-situ techniques can be utilized to achieve stoichiometric control in ultrathin films.