Bond type, polarisation and electron conduction in some oxide and chalcogenide glasses

Abstract

Although it is commonly accepted that the mechanism of switching must differ in detail in the numerous systems in which it has now been reported, the close parallelism between the electrical phenomena suggests that a common and fundamental process remains to be found as the prime cause of the various effects.The systems in which bistable (memory) switching occurs, can be divided into two groups; two — or morecomponent metal oxide system, and single or multi-component metal chalcogenide system, and in every case the systems either are glasses or are closely related to known vitreous compositions. It is reasonable to assume that the tendency of a system to form a glass and its ability to show electrical bistable behaviour are intimately related. This paper is an attempt to sketch a framework for such a correlation and to follow through some of the implications.The first part will present a view of the structure of the vitreous state which is to be used in the second part to develop a model of switching covering both oxide and chalcogenide systems, and in the third part some results on the thermoelectric properties of some copper phosphate glasses are reported and their implications considered.