Gas-Sensitive Electrical Conduction and its Mechanism in a Ag/Insulator System with Locally Discontinuous Structure

Abstract
The gas-sensitive electrical conduction of a locally discontinuous Ag-thin-film/insulator element is described and its mechanism is discussed on the basis of experimental results. A thin-film element was found to show essentially the same gas-sensing phenomenon as had been previously reported in a conglomerate element, which is a dispersion of Ag ultrafine particles within a porous matrix. A filament model is proposed to explain the gas-sensing phenomenon in terms of the ionic movement of Ag as well as the structural stability of the Ag filaments.