Patent ID: 7704906

Claim:
A method of producing a semiconductor porcelain composition having a composition formula expressed as [(BiNa) x (Ba 1-y R y ) 1-x ]TiO 3 , wherein R is at least one selected from the group consisting of La, Dy, Eu, Gd and Y and wherein x and y respectively satisfy 0<x≦0.2 and 0<y≦0.02, said method comprising: preparing a calcined powder of (BaR)TiO 3 , wherein R is defined as above, preparing a calcined powder of (BiNa)TiO 3 , mixing the calcined powder of (BaR)TiO 3 and the calcined powder of (BiNa)TiO 3 , and forming and sintering said mixed calcined powder to provide the semiconductor porcelain composition, wherein a calcination temperature in the preparing of the calcined powder of (BaR)TiO 3 is 900° C. through 1300° C. and a calcination temperature in the preparing of the calcined powder of (BiNa)TiO 3 is 700° C. through 950° C. and wherein the calcination temperature in the preparing of the calcined powder of (BiNa)TiO 3 is lower than the calcination temperature in the preparing of the calcined powder of (BaR)TiO 3 , and wherein the sintering is carried out in an inert gas atmosphere having an oxygen concentration of less than 1% and a treatment at an elevated temperature in an oxidizing atmosphere after the sintering is not carried out.