Ag-migration effects on the metastable phase in CaCu3Ti4O12 capacitors

Abstract

The silver migration effect into the metastable phase forms a micro-electric path, to enhance the relative dielectric permittivity of CaCu3Ti4O12 ceramics for electronic devices. Controlling the sintering time uniquely develops the metastable phase of as-sintered CaCu3Ti4O12 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 CaCu3Ti4O12 ceramics sintered for 2 h is 565.9 × 103, almost 52 times higher than that of the as-sintered CaCu3Ti4O12 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 CaCu3Ti4O12 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 CaCu3Ti4O12 ceramics.

Synthesis of CaCu3Ti4O12 utilizing eggshell waste as a calcium source: Structure, morphology, and dielectric properties

“…CCTO is also used as a photoanode for photocatalysis and photoelectrocatalysis in solar energy conversion [10]. Despite these significant advances, CCTO's technological applications are limited by its high dielectric loss, which is linked to its grain boundary conductivity [11]. Dielectric permittivity is directly proportional to dielectric loss, which is related to leakage current [12].…”