Reversible switching between pressure-induced amorphization and thermal-driven recrystallization in VO2(B) nanosheets

Pressure-induced amorphization (PIA) and thermal-driven recrystallization have been observed in many crystalline materials. However, controllable switching between PIA and a metastable phase has not been described yet, due to the challenge to establish feasible switching methods to control the pressure and temperature precisely. Here, we demonstrate a reversible switching between PIA and thermally-driven recrystallization of VO 2 (B) nanosheets. Comprehensive in situ experiments are performed to establish the precise conditions of the reversible phase transformations, which are normally hindered but occur with stimuli beyond the energy barrier. Spectral evidence and theoretical calculations reveal the pressure–structure relationship and the role of flexible VO x polyhedra in the structural switching process. Anomalous resistivity evolution and the participation of spin in the reversible phase transition are observed for the first time. Our findings have significant implications for the design of phase switching devices and the exploration of hidden amorphous materials. Pressure can either make materials more disordered, like amorphization, or more thermodynamic stable, yet the switching between the two metastable phases has not been described. Wang et al . study it in vanadium oxide nanosheets and highlight the role played by spin and charge during the transition.