Thermistors manufactured from nioubium oxide in the ZrO2-Bi2o3 / Termistores manufacturados de óxido de nioúbio no ZrO2-Bi2o3

Abstract

Thermistors are thermal resistors that allow high changes in the dielectric constant due to the sensible temperature change. The thermistors can be P.T.C.R and N.T.C.R. They are devices applied within the oil exploration industry, automobiles and electronics. The ceramic powders were obtained from stoichiometric quantities by ball milling with subsequent compaction, sintering and heat treatment from 825 ° C for 24 hours and cooled to room temperature. The samples were characterized by X-ray diffraction, scanning electron microscopy, calculation of the apparent density, dielectric constant and qualitative thermistor factors, called temperature coefficient and characteristic ratio. The samples from the mixture between the niobium zirconia-bismuth oxides obtained significant results for commercial and industrial application in the respective temperature ranges, between 30ºC-80ºC and 460ºC-600ºC.