External-strain induced insulating phase transition in VO₂nanobeam and its application as flexible strain sensor.

[∗] Dr. B. Hu , Y. Ding , D. Kulkarni , Y. Shen , Prof. V. V. Tsukruk , Prof. Z. L. Wang School of Materials Science and Engineering Georgia Institute of Technology Atlanta, GA 30332-0245 (USA) E-mail: [email protected] Dr. B. Hu , Prof. W. Chen State Key Laboratory of Advanced Technology for Materials Synthesis and Processing School of Materials Science and Engineering Wuhan University of Technology Wuhan, 430070 (P. R. China) E-mail: [email protected] Vanadium dioxide (VO 2 ), one of the most extensively studied structures in the correlated electron material family, undergoes a fi rst-order insulator (low-temperature) to metal (high-temperature) transition (MIT) near room temperature ( ∼ 68 ° C), which is simultaneously accompanied by a structural transition from a monoclinic (M) insulating structure to a rutile (R) metallic phase. Comparison of the percolative nature of MIT in two-dimensional polycrystalline VO 2 thin fi lms or VO 2 nanoplatelets, [ 1 , 2 ] and one-dimensional VO 2 morphology, especially on the nanometer-scale, is fi nding its way into functional device applications owing to its single-crystal structure with homogeneous phase and dislocation-free volume along with homogeneous domains. These structural characteristics account for the occurrence of MIT over a much narrower temperature range. [ 3 , 4 ]