Vanadium Dioxide

Vanadium dioxide (VO2) undergoes a metal-insulator transition (MIT) on cooling through a critical temperature Tc ~ 340 K. The resistivity increases by four orders of magnitude as the transition proceeds over a width of approximately 3 K [1]. The transition has also been induced by applied electric field [2]. Whether Joule heating or the electric field itself drives the transition is still controversial.

A structural transition is also associated with the MIT. The microscopic mechanism of the MIT in VO2 has been the subject of debate for decades because the time and temperature scales of the structural and electronic transitions are so similar that it is difficult to determine how the two are related. Some contend that the MIT is a Peierls-type structurally driven transition [3], while others argue that electron-electron interactions drive the transition [4]. VO2 is therefore a prime candidate to study the complex interplay of electron and lattice degrees of freedom in a strongly correlated electron system that exhibits an electronic phase transition. Additionally, since VO2 exhibits its interesting electronic behavior near room temperature, it is ideal for use in novel devices that can be integrated into existing technology.

[1] M. M. Qazilbash, M. Brehm, G. O. Andreev, A. Frenzel, P.-C. Ho, Byung-Gyu Chae, Bong-Jun Kim, Sun Jin Yun, Hyun-Tak Kim, A. V. Balatsky, O. G. Shpyrko, M. B. Maple F. Keilmann, and D. N. Basov. Physical Review B 79, 075107 (2009). (link)
[2] B. G. Chae, H. T. Kim, D. H. Youn, and K. Y. Kang. Physica B 369, 76 (2005). (link)
[3] J. B. Goodenough, J. Solid State Chem. 3, 490 (1971). (link)
[4] M. M. Qazilbash, M. Brehm, Byung-Gyu Chae, P.-C. Ho, G. O. Andreev, Bong-Jun Kim, Sun Jin Yun, A. V. Balatsky, M. B. Maple, F. Keilmann, Hyun-Tak Kim, and D. N. Basov, Science 318, 1750 (2007). (link)