A Rational Fabrication Method for Low Switching-Temperature VO2
Autor: | Benjamin Kalas, Zsófia Baji, J. Volk, Zsolt Czigány, Peter Petrik, László Pósa, György Molnár |
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Rok vydání: | 2021 |
Předmět: |
010302 applied physics
Thermal oxidation Fabrication Materials science thermal oxidation Annealing (metallurgy) General Chemical Engineering Analytical chemistry Vanadium chemistry.chemical_element 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences lcsh:Chemistry lcsh:QD1-999 Electrical resistance and conductance chemistry phase transition 0103 physical sciences General Materials Science Electrical measurements thermochromism Selected area diffraction 0210 nano-technology Refractive index |
Zdroj: | Nanomaterials Volume 11 Issue 1 Nanomaterials, Vol 11, Iss 212, p 212 (2021) |
ISSN: | 2079-4991 |
Popis: | Due to its remarkable switching effect in electrical and optical properties, VO2 is a promising material for several applications. However, the stoichiometry control of multivalent vanadium oxides, especially with a rational deposition technique, is still challenging. Here, we propose and optimize a simple fabrication method for VO2 rich layers by the oxidation of metallic vanadium in atmospheric air. It was shown that a sufficiently broad annealing time window of 3.0&ndash 3.5 h can be obtained at an optimal oxidation temperature of 400 ° C. The presence of VO2 was detected by selected area diffraction in a transmission electron microscope. According to the temperature dependent electrical measurements, the resistance contrast (R30 ° C/R100 ° C) varied between 44 and 68, whereas the optical switching was confirmed using in situ spectroscopic ellipsometric measurement by monitoring the complex refractive indices. The obtained phase transition temperature, both for the electrical resistance and for the ellipsometric angles, was found to be 49 ± 7 ° C, i.e., significantly lower than that of the bulk VO2 of 68 ± 6 ° C. |
Databáze: | OpenAIRE |
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