Dielectric Spectroscopy of Strongly Correlated Electronic States of Vanadium Dioxide


Cite item

Full Text

Open Access Open Access
Restricted Access Access granted
Restricted Access Subscription Access

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

Supplementary files

Supplementary Files
Action
1. JATS XML

Copyright (c) 2018 Pleiades Publishing, Ltd.