Highly repeatable nanoscale phase coexistence in vanadium dioxide films

TL;DR

This paper demonstrates that nanoscale phase coexistence in sputtered VO2 films during the metal-insulator transition is highly reproducible, paving the way for reliable nanoscale VO2-based devices.

Contribution

It reveals that nanoscale phase domain patterns in VO2 films are reproducible, challenging the belief that randomness affects phase formation in such materials.

Findings

Nanoscale phase patterns are highly reproducible in VO2 films.

Suppression of nanoscale randomness enhances device reliability.

Reproducible phase behavior enables potential applications in nanoscale devices.

Abstract

The metal-insulator transition (MIT) in vanadium dioxide (VO2) has the potential to lead to a number of disruptive technologies, including ultra-fast data storage, optical switches, and transistors which move beyond the limitations of silicon. For applications, VO2 films are deposited on crystalline substrates to prevent cracking observed in bulk VO2 crystals across the thermally driven MIT. Near the MIT, VO2 films exhibit nanoscale coexistence between metallic and insulating phases, which opens up further potential applications such as memristors, tunable capacitors, and optically engineered devices such as perfect absorbers. It is generally believed that the formation of phase domains must be affected to some extent by random processes which lead to unreliable performance in nanoscale MIT based devices. Here we show that nanoscale randomness is suppressed in the thermally driven MIT in sputtered VO2 films; the observed domain patterns of metallic and insulating phases in the vicinity of the MIT in these films behave in a strikingly reproducible way. This result opens the door for realizing reliable nanoscale VO2 devices.