Barium titanate based positive temp. coefft. thermistor compsn. - contg. silicon, niobium(yttrium), lithium and manganese oxides

摘要

A compsn. for a positive temp. coefft. (PTC) thermistor is based on BaTiO3, with the addn. of SiO2, either Nb2O5 or Y2O3, a Li cpd. decomposing to Li2O on calcining in air and either MnO2 or a Mn cpd. decomposing to a Mn oxide on calcining in air. The amt. of the additives used pref. is 0.05-1.24 wt.% SiO2, 0.007-0.09 wt.% Li cpd., 0.003-0.04 wt.% Mn cpd. and 0.05-0.22 wt.% Nb2O5 or 62oO3. This compsn. gives a high rupture potential, high instantaneous current on applying the potential, with rapid fall in this current, low specific resistance and good stability of the specific resistance.