Relaxation of the dielectric response in thin films of vanadium dioxide

Abstract

The results of studying the processes of dielectric relaxation in thin nanocrystalline films of vanadium dioxide are presented. The existence of a non-Debye relaxation process was revealed, which is due to the presence of a distribution of relaxators over relaxation times according to the Cole-Davidson model. The activation energy of the dielectric relaxation process was found to be Ep = (0.9 ± 0.1) eV. The observed regularities are explained by a model which views the system as a set of relaxators whose physical parameters have different numerical values due to the Gaussian size distribution of nanocrystallites of the VO2 film. The temperature change in the parameters of the dielectric relaxation process, detected at T = 340 K, indicates that a complex Mott-Peierls semiconductor-metal phase transition occurs at a given temperature in the VO2 nanocrystalline film.

Keywords

• dielectric response
• thin films
• vanadium dioxide
• distribution of relaxors
• relaxation time distribution function