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 matrix of polyethylene glycol (PEG) doped with a quaternary ammonium salt (QAS), namely tetraethylammonium bromide. It has been established that under the influence of the dopant the heating of a sample up to the temperature of the metal-semiconductor phase transition (MSPT) results in a phase in homogeneity of the sample. On the basis of the results of this study it is possible to conclude that small concentrations of QAS in a PEG matrix can exert a strong effect on the electronic structure of dispersed VO₂ particles. This is accompanied by the appearance of phase heterogeneity of VO₂ which manifests itself in the fact that - with the onset of MSPT with increasing temperature - one portion of the substance passes into the metallic state, and the other remains in the semiconductive state. This revised version was published online in August 2006 with corrections to the Cover Date.