• Fulltext

       

        Click here to view fulltext PDF


      Permanent link:
      https://www.ias.ac.in/article/fulltext/boms/031/06/0835-0839

    • Keywords

       

      Tungsten oxide; hydrotungstite; humidity sensor; selectivity; protonic conduction.

    • Abstract

       

      Thin films of the hydrated phase of tungsten oxide, hydrotungstite (H2WO4.H2O), have been grown on glass substrates using a dip-coating technique. The 𝑏-axis oriented films have been characterized by X-ray diffraction and scanning electron microscopy. The electrical conductivity of the films is observed to vary with humidity and selectively show high sensitivity to moisture at room temperature. In order to understand the mechanism of sensing, the films were examined by X-ray diffraction at elevated temperatures and in controlled atmospheres. Based on these observations and on conductivity measurements, a novel sensing mechanism based on protonic conduction within the surface layers adsorbed onto the hydrotungstite film is proposed.

    • Author Affiliations

       

      G V Kunte1 S A Shivashankar1 A M Umarji1

      1. Materials Research Centre, Indian Institute of Science, Bangalore 560 012, India
    • Dates

       

© 2017 Indian Academy of Sciences, Bengaluru.