Some Switching Characteristics of Calcium Borate Glasses Containing Iron

摘要

A series of calcium borate glasses containing from about 10 to 30 mole% Fe203 was investigated. Electrical switching phenomena were observed in all the samples. The threshold voltage decreased by a factor of about one hundred as the concentration of iron increased beyond 20 mole% Fe203. On the other hand, the threshold voltage increased with sample thickness and decreasing temperature for the same iron content. Negative resistance was sometimes observed before the samples were converted from the OFF to the ON state. A memory effect was also observed upon exceeding a certain threshold current. The switching phenomena (whether negative resistance or switching with memory effects) in the calcium borate glasses containing iron can be tentatively explained on the basis of a simple theory of Joule microheating. (Author)