Influence of tetraethylammonium bromide on phase inhomogeneity of disperse vanadium dioxide particles in matrix of polyethylene glycol

A study has been made on samples of disperse vanadium dioxide VO2.in a matrix Ms1500.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 inhomogeneity of the sample. One portion of the disperse VO2 particles passes to the metallic state, while others retain its semiconducting state. The possible cause for the observed phenomenon is the emergence of strong local electric fields between the QAS cations and the VO2 surface. In the region of phase heterogeneity, the MSPT temperature for the semiconducting phase is shifted into a higher temperature interval. q2000 Elsevier Science B.V. All rights reserved.