Investigating Insulator–Metal Transitions in Ti₂O₃/MnTiO₃ Superlattices

Insulator–metal transition (IMT) materials, which exhibit a rapid switch between conductive and insulating states through electronic phase transitions, are promising for various microelectronic applications, including memory devices and radio-frequency antennas. However, existing IMT compounds face a tradeoff between two key figures of merit: transition temperature and resistivity change ratio. To address this challenge, one promising approach is to form digital superlattices of two different components and harness the interfacial structure as an emergent phase participating in the IMT. In this study, we investigate the IMT behavior in Ti₂O₃/MnTiO₃ superlattices using first-principles density functional theory (DFT) calculations. By modeling changes in the band alignment and electron density at the interfaces with changes in superlattice periodicity, we identify the role of charge transfer as a driving force for the transition supported by differential atomic relaxations. We further explore the influence of layer thicknesses, correlation effects (characterized by the Hubbard U), and magnetic ordering on the IMT. This work establishes a robust, reusable workflow for studying IMT in superlattices, from which we will develop data-driven models to predict and design IMT behaviors in heterogeneous metal oxide superlattices.