Ag-migration effects on the metastable phase in CaCu(3)Ti(4)O(12) capacitors

The silver migration effect into the metastable phase forms a micro-electric path, to enhance the relative dielectric permittivity of CaCu(3)Ti(4)O(12) ceramics for electronic devices. Controlling the sintering time uniquely develops the metastable phase of as-sintered CaCu(3)Ti(4)O(12) ceramics. A post-heating process that applies the migration of silver into the metastable phase increases the relative dielectric permittivity. At 1 kHz frequency, the relative dielectric permittivity at room temperature of the silver-migrated CaCu(3)Ti(4)O(12) ceramics sintered for 2 h is 565.9 × 10(3), almost 52 times higher than that of the as-sintered CaCu(3)Ti(4)O(12) ceramics. The selected area electron diffraction (SAED) patterns of the large and small grains were similar, but differed from those of the metastable region, including the grain boundary of the as-sintered CaCu(3)Ti(4)O(12) ceramics sintered for 2 h by TEM technique. This phenomenon suggests that enabling Ag-migration into the metastable phase develops a micro-electric path that improves the relative dielectric permittivity of CaCu(3)Ti(4)O(12) ceramics.