We report the characteristics of a voltage-induced metal-insulator transition (MIT) in macro-sized VO2 crystals. The square of MIT onset voltage (VCMIT2) value shows a linear dependence with the ambient temperature, suggesting that the Joule heating effect is the likely cause to the voltage-induced MIT. The combination of optical microscope images and Laue microdiffraction patterns show the simultaneous presence of a metallic phase in the bulk of the crystal with partially insulating surface layers even after the MIT occurs. A large asymmetry in the heating power just before and after the MIT reflects the sudden exchange of Joule heat to its environment.
Bibliographical noteFunding Information:
H. L. Ju and B. S. Mun would like to thank the support by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (2012R1A1A2006948 and 2012R1A1A2001745). The Advanced Light Source is supported by the Director, Office of Science, Office of Basic Energy Sciences, Materials Science Division, of the US Department of Energy under Contract No. DE-AC02-05CH11231 at LBNL. The microdiffraction program at the ALS on BL 12.3.2 was made possible by NSF Grant No. 0416243. This paper was supported by GIST College's 2013 GUP Research Fund.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)