In-Situ Resistivity for Precise Control of Phase Transitions in Functional Oxides

Controlled post-growth annealing is essential for stabilizing functional oxides, as oxygen stoichiometry strongly influences crystalline ordering and electronic properties. Uncontrolled annealing can lead to unwanted phase evolution and degradation, motivating real-time probes of properties during thermal treatment. We report the development of an in-situ resistivity measurement and real-time plotting system integrated into a tube furnace, designed to operate at temperatures up to 400 °C and under a variety of gas environments, including ozone. By monitoring resistivity during annealing, this approach enables the identification of optimal processing conditions, provides insight into oxygen-driven phase transitions, and facilitates on-the-fly materials-by-design. Preliminary measurements on thin film transition metal oxides demonstrate reproducible resistivity evolution during thermal cycling. In addition, the effectiveness of capping layers in mitigating oxygen-loss-induced degradation is investigated, highlighting their role in controlling soft-chemistry-driven phase evolution. This platform offers a versatile tool for improving the stability and functional performance of oxides.