Conductivity stabilization by metal and oxide additives in ceramics on the basis of VO2 and glass V2O5–P2O5

Abstract Conductivity behavior during the temperature cycling through the phase transition temperature of VO 2 ( T t = 68 °C) was investigated in glass-ceramics based on VO 2 and vanadium phosphate glass (VPG) for compositions without and with Cu and SnO 2 additives. Copper and SnO 2 additives stabilize the conductivity of glass-ceramics at temperature cycling. For ceramics (wt%) (80 − y )VO 2 –5Cu–15VPG– y SnO 2 the best stabilizing effect takes place when SnO 2 content is in the interval 35 wt% y 2 content keeps a stable value of the conductivity change (∼10 2 ) in the vicinity of VO 2 phase transition temperature and shows the conductivity decrease no more than of 2.5 times after 3000 thermal cycles. The reasons of conductivity stabilizing in VO 2 -based glass-ceramics with additives of Cu and SnO 2 are being discussed. The analysis resting on the percolation theory has shown the increase of conductivity stability in VO 2 -based glass-ceramics when the VO 2 volume fraction and the average size of VO 2 crystallites decrease and the ceramics surface tension increases.