Dielectric Spectroscopy of Strongly Correlated Electronic States of Vanadium Dioxide
- Authors: Il’inskii A.V.1, Kastro R.A.2, Nikulin E.I.1, Shadrin E.B.1
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Affiliations:
- Ioffe Institute
- Herzen State Pedagogical University
- Issue: Vol 63, No 6 (2018)
- Pages: 851-856
- Section: Physics of Nanostructures
- URL: https://journal-vniispk.ru/1063-7842/article/view/201521
- DOI: https://doi.org/10.1134/S1063784218060129
- ID: 201521
Cite item
Abstract
The thermal evolution of the conductivity of a VO2 film and database-obtained band gap Eg of film nanocrystallites is traced in the temperature range of –196°C < T < 100°C (77 K < T < 273 K); the level position of donor impurity centers is determined to be Ed = 0.04 eV. It is shown that energy Eg decreases from 0.8 to ∼0 eV with an increase in temperature in the range of 273 K < T < 300 K, which is caused by the narrowing of the energy gap due to correlation effects and considered as the temperature-extended Mott “insulator–metal” electron phase transition with the monoclinic lattice symmetry retained. The subsequent jump in the symmetry from monoclinic to tetragonal with a further increase in temperature is considered as the Peierls structural phase transition, the temperature of which is in the vicinity of 340 K and determined by the size effects, nonstoichiometry of VO2 film nanocrystallites, and degree of their adhesion to the substrate.
About the authors
A. V. Il’inskii
Ioffe Institute
Author for correspondence.
Email: ilinskiy@mail.ioffe.ru
Russian Federation, St. Petersburg, 194021
R. A. Kastro
Herzen State Pedagogical University
Email: ilinskiy@mail.ioffe.ru
Russian Federation, St. Petersburg, 191186
E. I. Nikulin
Ioffe Institute
Email: ilinskiy@mail.ioffe.ru
Russian Federation, St. Petersburg, 194021
E. B. Shadrin
Ioffe Institute
Email: ilinskiy@mail.ioffe.ru
Russian Federation, St. Petersburg, 194021
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