TiN/CaCu3Ti4O12 binary ceramics with tunable and weakly negative permittivity

Abstract In this paper, the titanium nitride/copper calcium titanate (TiN/CCTO) composites were prepared by low-temperature sintering. The negative permittivity was observed when TiN content exceeded 50 wt.% due to plasma oscillation phenomenon, and the weakly negative permittivity was ascribed to a moderate electron density in TiN/CCTO composites. Meanwhile, the alternating current (AC) conduction behavior was transformed from hopping to metal-like along with a skin effect. Furthermore, the equivalent circuit analysis indicated that the positive reactance values were responsible for negative permittivity, leading to the inductive character in TiN/CCTO composites. The fabricated TiN/CCTO binary ceramic composites with tunable and weakly negative permittivity are devoted to promoting the research in novel capacitors and attenuation.