TiN/CaCu3Ti4O12 binary ceramics with tunable and weakly negative permittivity

• Published in: Materials letters 2021-01, Vol.283, p.128824, Article 128824
• Main Authors: Wang, ZongXiang, Sun, Kai, Qu, YunPeng, Qin, JinYuan, Tian, Jiahong, Li, Yaping, Li, XiaoFeng, Wang, Xuai, Fan, RunHua
• Format: Article
• Language: English
• Subjects: Alternating current; Attenuation; Calcium titanate; Ceramic composites; Composite materials; Electron density; Electronic materials; Equivalent circuits; Hopping conduction; Inductive character; Low temperature; Materials science; Metacomposites; Negative permittivity; Permittivity; Plasma oscillations; Reactance; Skin effect; Titanium nitride
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/j.matlet.2020.128824

•The weakly and near-zero negative permittivity is firstly observed in TiN/ CaCu3Ti4O12 binary ceramics metacomposites.•The weakly negative permittivity in binary ceramics metacomposites is ascribed to the great dilution of electrons in TiN.•Positive reactance is responsible for the negative permittivity, which is corresponding to an inductive character. 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.