METHOD OF PREPARING FERROELECTRIC CERAMICS

摘要

METHOD OF PREPARING FERROELECTRIC CERAMICS A process for preparing strengthened ferroelectric ceramics, which comprises sintering ceramic materials and then heat treating the sintered ceramics at a temperature from about 100.degree.C to about 400.degree.C lower than the final sintering temperature of ceramics, for about 1 to about 60 hrs., and then cooling at a rate from about 300.degree.C to about 10.degree.C per hour. Strengthened ferroelectric ceramics are obtained among the following ferroelectric ceramic compositions: I) Pb(¢B1!ATa1-A)O3-pbTiO3-pbZrO3, where ¢B1! is Mg, Zn, Cd, Sn, Mn, Fe, Co, and Ni when A=1/3 and ¢B1! is Li and Cu when A=1/4, II) Pb(¢B2!BTa1-B)O3-Pb(¢B3!CTa1-C)O3-PbTiO3-PbZrO3, where ¢B2! and ¢B3!, ¢B2!?¢B3!, are Mg, Zn, Cd, Sn, Mn, Fe, Co and Ni when B and C=1/3, and ¢B2! and ¢B3!, ¢B2!?¢B3!, are Li and Cu when B and C=1/4, III) Pb(¢B1!ATa1-A)O3PbTiO3-PbZrO3 with MnO2, where ¢B1! is Mg, Zn, Cd, Sn, Fe, Co and Ni when A=1/3, and ¢B1! is Li and Cu when A=1/4, and IV) Pb(¢B2!BTa1-B)O3-Pb(¢B3!CTa1-C)O3-PbTiO3-PbZrO3 with MnO2, where ¢B2! and ¢B3!, ¢B2!?¢B3!, are Mg, Zn, Cd, Sn, Fe, Co and Ni when B and C=1/3, and ¢B2! and ¢B3!, ¢B2!?¢B3!, are Li and Cu when B and C = 1/4.