Thermal behavior of dispersed vanadium dioxide particles in polyethylene glycol matrix containing tetraethylammonium bromide

A study has been made on samples of dispersed vanadium dioxide (VO2) in a m atrix of polyethylene glycol (PEG) doped with a quaternary ammonium salt (Q AS), namely tetraethylammonium bromide. It has been established that under the influence of the dopant the heating of a sample up to the temperature o f the metal-semiconductor phase transition (MSPT) results in a phase inhomo geneity of the sample. On the basis of the results of this study it is poss ible to conclude that small concentrations of QAS in a PEG matrix can exert a strong effect on the electronic structure of dispersed VO2 particles. Th is is accompanied by the appearance of phase heterogeneity of VO2 which man ifests itself in the fact that - with the onset of MSPT with increasing tem perature - one portion of the substance passes into the metallic state, and the other remains in the semiconductive state.