Thermal dynamics of VO2 films within the metal–insulator transition: Evidence for chaos near percolation threshold

Abstract

Published by the AIP PublishingArticles you may be interested in Studies on electric triggering of the metal-insulator transition in VO2 thin films between 77 K and 300 K Geometric confinement effects on the metal-insulator transition temperature and stress relaxation in VO2 thin films grown on silicon J. Appl. Phys. 109, 063512 (2011); 10.1063/1.3556756Thermal conductivity and dynamic heat capacity across the metal-insulator transition in thin film VO 2 Appl. Phys. Lett. 96, 151906 (2010); 10.1063/1.3394016 Near-zero IR transmission in the metal-insulator transition of V O 2 thin filmsThe thermal dynamics of thin vanadium dioxide films at the martensitic metal-insulator phase transition has been evaluated experimentally by thermal excitation spectroscopy. Over the transition region, the device becomes highly nonlinear, and its bolometric performance is affected. At low thermal cycling rates for a temperature around the percolation threshold, the device stochastically switches into an unusual pattern. The originally smooth and monotonic shape of the R(T) curve for minor loops suddenly becomes unstable and unpredictable. By direct observation of at least two strange attractors, the phenomenon clearly has been identified as chaotic. Bolometric performance of VO 2 based devices in the transition region may suffer strong degradation for low thermal cycling rates. In this region, sensor responsivity for periodic thermal excitation is significantly reduced. Resistance noise is 1/f -type and self-generated oscillations were observed at frequency Ͻ10 Ϫ2 Hz.

Nonlinear Phenomena and Deterministic Chaos in Systems With Vanadium Dioxide

“…It was shown that in the OFF state there was a mixture of a flicker noise and pre-breakdown generation-recombination fluctuations. The low-frequency noise of 1/f type has been also found in thin vanadium dioxide films [6] and in other materials exhibiting MITs (La2-xSrxMnO3, Fe3O4 [15]) as well.…”

“…Chaotic oscillations have been obviously first observed in [7]. The experimental works have been carried out on single crystals [5,8], thin films [6], [9], [10] and ceramics [7]. Chaotic dynamics and noise effects in vanadium dioxide are of considerable interest because of potential technical applications of the material.…”

“…Therefore, the VO2 based switching devices are expected to demonstrate complex behaviors, from ordinary noise to deterministic chaos. For example, low-frequency noise at the thermally induced MIT has been studied in [4]- [6], and the noise effects at electrical switching in VO2-based structuresin [7], [8]. Chaotic oscillations have been obviously first observed in [7].…”

“…As for the applied aspect, vanadium oxide films are used for fabrication of a variety of electrical and optical devices, including electrical switching elements, temperature sensors, optical storage devices, variable reflectivity mirrors, IR bolometric detectors [11]. The latter field of application is of especial interest [6], [11][12][13], because vanadium dioxide allows the designing of high-sensitive, spectrally broadband and uncooled bolometers. The study of noise and related phenomena in such devices is obviously an important problem from the viewpoint of the improvement of the bolometric sensor sensitivity and accuracy.…”

“…Chaotic dynamics and noise effects in vanadium dioxide are of considerable interest because of potential technical applications of the material. In addition, these effects receive increased attention due to general fundamental interest both in the nonlinear phenomena themselves, and, in particular, in the problem of metal-insulator transitions, because the noise measurements can give valuable information about the transition mechanism [4][5][6], [8], [10]. As for the applied aspect, vanadium oxide films are used for fabrication of a variety of electrical and optical devices, including electrical switching elements, temperature sensors, optical storage devices, variable reflectivity mirrors, IR bolometric detectors [11].…”