BARIUM TITANATE SEMICONDUCTOR CERAMIC, BARIUM TITANATE SEMICONDUCTOR CERAMIC COMPOSITION, AND PTC THERMISTOR FOR TEMPERATURE DETECTION

摘要

A PTC thermistor for temperature detection is provided which has low room-temperature resistance, a low detection temperature, and high detection accuracy. As the semiconductor ceramic 1, a barium titanate semiconductor ceramic is used which contains a Perovskite-type compound containing Ba, Ca, Sr and Ti as the main component, and which further contains R (R is at least one of Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu), Mn and Si. Setting the amount of Ti to 100 parts by mole, the barium titanate semiconductor ceramic in a melted state has x parts by mole of Ca, y parts by mole of Sr and z parts by mole of Mn, with 20 ≦ x ≦ 25, 19 ≦ y ≦ 25, and 0.01 ≦ z ≦ 0.03, and further, y ≧ -0.8x + 37 holds when 0.01 ≦ z 0.019 and y ≦ -x + 48 holds when 0.021 z ≦ 0.03.