Modulating the metal-to-insulator transition temperature in MnTiO3/γ-Ti3O5 superlattices 

Correlated oxide thin films that exhibit metal-to-insulator transitions (MIT) are of scientific and technological interest for applications in sensors, field-effect transistors, and neuromorphic computing. The ability to modulate the transition temperature and the magnitude of the resistivity change across the transition is essential for optimizing device performance. In this work, we explore the role of structural and electronic interactions in modulating the MIT in interfaces formed by molecular beam epitaxy between γ-Ti3O5 which exhibits an MIT around 130 K and insulating MnTiO3. These interactions are controlled by tuning the relative thicknesses of the γ-Ti3O5 and MnTiO3 layers in MnTiO3/γ-Ti3O5 superlattices with atomic-scale precision. Temperature-dependent transport measurements, high-resolution X-ray diffraction, and first-principles calculations reveal a systematic increase in both the transition temperature and resistivity change magnitude with increasing MnTiO₃ layer thickness. This observed modulation is attributed to a delicate balance of competing electronic and structural interactions at the heterointerface. Our findings demonstrate a pathway for engineering MIT behavior in oxide heterostructures through interface design.