Abstract: Hexagonal tungsten bronze was
prepared by high temperature gaseous permeation method from polyoxometalates
precursor This work demonstrates the feasibility of gas permeation
synthesis in large scale. The batch size was 10L, and the holding time was two
hours. XRD,
TG-DTA,XPS and AC impedance spectra
were used to characterize the resulting
material. The crystal structure
parameters of were obtained by the analysis of XRD, which are crystal
system: Hexagonal,
lattice parameter:The
XPS results confirmed the presence of the mixed valence state of tungsten. The
high temperature electrical properties were studied by AC impedance spectra.
Although the sample exhibits the semiconductive behavior, curves are not linear and it obeys
the small polaron hopping mechanism.
Keywords and phrases: tungsten bronzes, high temperature, gaseous permeation, polyoxometalates.
