Simple and fast fabrication of single crystal VO2 microtube arrays

Abstract

Abstract Single crystal VO 2 is a strongly correlated electron material that has shown great potential for a wide range of high-performance modern device applications, such as microbolometers, lithium ion batteries, microactuators and strain sensors. However, the present fabrication methods for single crystal VO 2 almost always require complicated procedures, strict conditions and long reaction times of up to one week. Here, we report a simple, fast, low-cost and green method for fabricating single crystal VO 2 using a thermal oxidation route based on resistive heating of a vanadium foil in air. Our method not only reduces the complete fabrication time from hours to tens of seconds but also naturally forms single crystal VO 2 microtube arrays that are nearly vertically aligned on the surface of a V 2 O 5 substrate. Microstructure characteristics and the reversible phase transition between the monoclinic VO 2 and rutile VO 2 phases demonstrate that the obtained single crystal VO 2 is the same as that achieved by other fabrication methods.