Phase management in single-crystalline vanadium dioxide beams

A systematic study of various metal-insulator transition (MIT) associated phases of VO2, including metallic R phase and insulating phases (T, M1, M2), is required to uncover the physics of MIT and trigger their promising applications. Here, through an oxide inhibitor-assisted stoichiometry engineering, we show that all the insulating phases can be selectively stabilized in single-crystalline VO2 beams at room temperature. The stoichiometry engineering strategy also provides precise spatial control of the phase configurations in as-grown VO2 beams at the submicron-scale, introducing a fresh concept of phase transition route devices. For instance, the combination of different phase transition routes at the two sides of VO2 beams gives birth to a family of single-crystalline VO2 actuators with highly improved performance and functional diversity. This work provides a substantial understanding of the stoichiometry-temperature phase diagram and a stoichiometry engineering strategy for the effective phase management of VO2. Control of the phases associated with the metal-insulator transition in VO2 underpins its applications as a phase change material. Here, the authors report phase management by means of oxide inhibitor-assisted growth and present high-performance VO2 actuators based on asymmetric phase transition routes.

Automated summary

This study demonstrates the selective stabilization of all insulating phases in single-crystalline VO2 beams at room temperature through oxide inhibitor-assisted stoichiometry engineering. The precise spatial control of phase configurations introduces a new concept of phase transition route devices. By combining different phase transition routes, high-performance VO2 actuators with improved performance and functional diversity are achieved.