Lyashkov A. Electron Processes in Molecules of Gas Sensitive Ceramic Structures on the Base of Zinc Oxide Doped with Silver

Object of investigation: the molecular-electronic processes, which is responsible for the formation of gas-sensitivity properties in semiconductor ceramic systems based on zinc oxide with a silver additive. The work purpose is definition of mechanisms of molecular-electronic processes passing, formation of electrical properties, their sensitivity and selectivity to saturated pairs of monohydric alcohols and water into ceramic zinc oxide with silver impurity. The assigned task solution is based on the using of a complex experimental and calculated methods which are consist of electric conductivity measurement in wide temperature range in different gas environment; measurement of thermovacuum curves of electric conductivity; dielectric spectroscopy; an electronic paramagnetic resonance. Structural ceramics features were investigated with optical and raster electronic microscopy, and also with the X-ray diffraction and element analysis. It was expanded representations about processes and mechanisms which are responsible for the formation of electronic conductivity sensitivity to burning and reducing gases in oxide-metallic materials. Their determined selectivity of gas-sensitivity properties to pairs of various alcohols gives them a prospect for semi-conductor sensor improvement and a wider using in industrial and a national economy. The developed and approved mathematical model of molecular-electronic processes at detecting of pairs of ethanol in air can be used for the prediction of gas-sensitivity characteristics of the sensor based on oxide materials. Technological parameters of the approved modes of manufacturing, electrophysical and gas-sensitivity parameters of some ceramic materials based on oxides of zinc, tin, tungsten, nickel and iron are shown. Application area is design of selective sensor of burning and reducing gases.