Novel Gas Detection Method by Metal-Insulator Conglomerate

Ultra-fine silver particles of a nominal size of 4 nm were dispersed in a a porous structure of SiO2 by a wet chemical reaction method. This conglomerate changed its electric resistance by the kind of the ambient gases and can be used as a gas-detecting element. The electric response to the exchange between oxygen and ethylene containing atmospheres was suitably called switching, which was quite rapid and had a threshold voltage. The switching was reversible and repeatable, showing a memory effect.