Metal‐to‐insulator transition in oxide semimetals by anion doping

Oxide semimetals exhibiting both nontrivial topological characteristics stand as exemplary parent compounds and multiple degrees of freedom, offering a promise for the realization of novel electronic states. In this work, we report the structural and transport phase transition in an oxide semimetal, SrNbO3, achieved through effective anion doping. Notably, the resistivity increased by more than three orders of magnitude at room temperature upon nitrogen‐doping. The extent of electronic modulation in SrNbO3 is strongly correlated with misfit strain, underscoring its phase instability to both chemical doping and crystallographic symmetry variations. Using first‐principles calculations, we discern that elevating the level of nitrogen doping induces an upward shift in the conductive bands of SrNbO3−δNδ. Consequently, a transition from a metallic state to an insulating state becomes apparent as the nitrogen concentration reaches a threshold of 1/3. This investigation shows effective anion engineering in oxide semimetals, offering pathways for manipulating their physical properties. Using effective anion doping, profound structural and transport phase transition is achieved in a recently uncovered oxide semimetal, SrNbO3, thin films, demonstrating the potential of anion engineering offers straightforward pathways for manipulating ground states of functional materials. Anion doping effectively modified the crystallographic structure and electronic band structure, thus dramatically changing the macroscopic physical properties of correlated Dirac semimetals.