Vanadium dioxide $\left(\mathrm{V}{\mathrm{O}}_2\right)$ undergoes a phase transition between an insulating monoclinic phase and a conducting rutile phase. Like other correlated electron systems, the properties of $\mathrm{V}{\mathrm{O}}_2$ can be extremely sensitive to small changes in external parameters such as strain. In this paper, we investigate a compressively strained $\mathrm{V}{\mathrm{O}}_2$ film grown on (001) quartz substrate in which the phase transition temperature $\left(T_{\mathrm{c}}\right)$ has been depressed to 325 K from the bulk value of 340 K. Infrared and optical spectroscopy reveals that the lattice dynamics of this strained film are similar to unstrained $\mathrm{V}{\mathrm{O}}_2$. However, some of the electronic interband transitions of the strained $\mathrm{V}{\mathrm{O}}_2$ film are significantly shifted in energy from those in unstrained $\mathrm{V}{\mathrm{O}}_2$. The lattice dynamics remain largely unchanged while the $T_{\mathrm{c}}$ and some of the electronic interband transitions differ substantially from the bulk values, which highlights the role of electronic correlations in driving this metal-insulator phase transition.

• Received 23 July 2014
• Revised 10 April 2015

DOI:https://doi.org/10.1103/PhysRevB.91.205140