BARIUM TITANATE-BASED SEMICONDUCTOR PORCELAIN

PURPOSE:To reduce fluctuation both in resistance due to temperature change in use environment and in specific resistance value at ordinary temperature and enable excellent communication in normal use when used for communication protectors by substituting part of barium in a barium titanate based semiconductor porcelain with a specific element and forming a solid solution. CONSTITUTION:At least one selected from the group of rare earth elements, Y, Nb, Sb and Bi as a minor additive are added to BaTiO3 or a barium titanate-based porcelain composition consisting essentially of the BaTiO3 and containing Sr, Sn or Zr added for controlling the Curie point and further plural auxiliary additives for improving PTC characteristics. In the resultant barium titanate-based semiconductor porcelain, the following constitutions (a) to (c) are adopted. Part of Ba is simultaneously substituted with (a) 0.001-0.1 atomic% Mg and 0.01-2.0 atomic% Ca to form a solid solution, (b) 0.01-5.0 atomic% Pb and 0.01-2.0 atomic% Ca to form a solid solution or (c) 0.001-0.1 atomic% Mg, 0.01-5.0 atomic% Pb and 0.01-2.0 atomic% Ca to form a solid solution.