MgTiO3 (003) Thin Film Deposited on Sapphire (0001) by Sputtering

This work demonstrates the epitaxy of ilmenite magnesium titanate (MgTiO3) thin films on c‐plane sapphire. MgTiO3 thin film with a (003) preferred‐orientation was obtained by adjusting the substrate temperature, annealing temperature, and annealing time; (111)‐preferring spinel Mg2TiO4 was found when magnesium titanate thin films were deposited at room temperature and then postannealed. X‐ray diffraction was used to identify the orientation and quality of the crystal, providing information that is useful in elucidating the epitaxial relationships between the MgTiO3/sapphire and Mg2TiO4/sapphire interfaces. The optical properties of the MgTiO3 were measured, and (003)‐preferring MgTiO3 was found to be a good candidate for optical applications.