An engineering design based on nano/micro-sized composite for CaTiO3/CaCu3Ti4O12 materials and its dielectric and non-Ohmic properties. Issue 17 (1st December 2019)

• Record Type: Journal Article
• Authors: Maleki Shahraki, Mohammad; Daeijavad, Hossein; Emami, Amir Hossein; Abdollahi, Mehdi; Karimi, Asadollah
• Is Part Of: Ceramics international. Volume 45:Issue 17(2019)Part A
• Page Start: 21676
• Page End: 21683
• Publication Date: 2019-12-01
• Subjects: Micron-sized CaCu3Ti4O12 -- Nano-sized CaTiO3 -- Composite -- Dielectric -- Non-Ohmic; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2019.07.166
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: In this research, the dielectric and non-Ohmic properties of nano/micro-sized CaTiO3 /CaCu3 Ti4 O12 composites (NCTO/MCCTO) with different weight percent of CTO (0, 7, 15, and 30 wt% ) were examined as a new engineering design. NCTO was prepared after high energy ball milling of calcined CaCO3 and TiO2 mixture. Micro-sized CCTO was synthesized after calcination of CaCO3, CuO, and TiO2 mixture at 1000 °C. According to the TEM, BET, and SEM analyses; the mean particle size of NCTO and MCCTO was 80 nm and 2.5 μm, respectively. The NCTO/MCCTO powder composites were prepared from direct mixing of pre-synthesized NCTO and MCCTO. After the sintering of green body composites at 1100 °C for 5 h, both relative density and grain size of NCTO/MCCTO composites decreased with the increase in NCTO content. It was found that the abnormal grain growth in the sintered MCCTO changed to the normal grain growth in NCTO/MCCTO composites. The best dielectric properties ( ϵ r : 7050, tanδ : 0.02) was observed for NCTO/MCCTO with 15 wt% CTO. This unique dielectric constant was ascribed to the large grain size of CCTO, and the reduced dead zone of CTO with a low dielectric constant. Due to uniform distribution of CTO with the small size of 0.3–1.5 μm at grain boundaries of CCTO with a large grain size of 5 μm, the number of active interfaces were increased sharply and consequently the maximum breakdown electric field of 7 kV/cm and the nonlinear coefficient of 15 were obtained for NCTO/MCCTO with 15 wt% of NCTO. Therefore, the MCCTO-NCTO composite with 15 wt% of NCTO is a promising candidate for the capacitor and energy storage applications.