Low dielectric loss induced by coupling effects of donor-acceptor ions in (Nb+Al) co-doped rutile TiO2 colossal permittivity ceramics. Issue 6 (15th April 2018)

• Record Type: Journal Article
• Authors: Yu, Yang; Zhao, Yu; Zhang, Tian-Dong; Song, Rui-Xuan; Zhang, Yu-Lei; Qiao, Yu-Long; Li, Wei-Li; Fei, Wei-Dong
• Is Part Of: Ceramics international. Volume 44:Issue 6(2018)
• Page Start: 6866
• Page End: 6871
• Publication Date: 2018-04-15
• Subjects: Colossal permittivity -- Co-doped rutile TiO2 ceramics -- Ionic-pair; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2018.01.111
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: Colossal dielectric properties in donor-acceptor co-doped rutile TiO2 ceramics have attracted increased interest in recent years. However, dielectric loss (tan δ) of (Nb+Al) co-doped TiO2 ceramics are quite scattered in the previous studies. Here, we show the dielectric properties of (Nb+Al) co-doped rutile TiO2 ceramics are sensitive to sintering and ageing technologies, which is related to the coupling behavior of acceptor-donor ions. Both permittivity and dielectric loss of as-sintered (Nb+Al) co-doped TiO2 ceramics are very large, and increase with the sintering time increasing. After ageing treatment at 900 °C, the dielectric loss of co-doped ceramics reduces from 139 to 0.15 in a wide frequency range. Based on the X-ray diffraction and complex impedance analyses, it can conclude that Nb 5+ -Al 3+ pair formation during ageing treatment reduces the concentration of oxygen vacancy, resulting in the decreases of the conductivity and dielectric loss. The changes in dielectric response of (Nb+Al) co-doped TiO2 ceramics clearly suggest that ageing process is an effective way for the Nb 5+ and Al 3+ ions to form the Nb 5+ -Al 3+ pairs. We believe that the coupling effect of donor-acceptor ions is a practical and feasible route to reduce the dielectric loss of (Nb+Al) co-doped TiO2 ceramics for high-energy-density storage applications.