Crystal structure and dielectric properties of Bi2O3-CaO-Nb2O5 compounds. (15th February 2017)

• Record Type: Journal Article
• Authors: Gao, Libin; Tang, Ke; Xu, Jiaming; Xu, Zhengrui
• Is Part Of: Materials & design. Volume 116(2017)
• Page Start: 109
• Page End: 114
• Publication Date: 2017-02-15
• Subjects: Dielectric properties -- Pyrochlore -- Bismuth based dielectric materials -- Crystal structure -- Low dielectric loss; Materials -- Periodicals; Engineering design -- Periodicals; Matériaux -- Périodiques; Conception technique -- Périodiques; Electronic journals; 620.11
• DOI: 10.1016/j.matdes.2016.12.006
• Languages: English
• ISSNs: 0264-1275

Abstract

Abstract: The Bi2 O3 -CaO-Nb2 O5 (BCN) materials were prepared by solid-state reaction. The BCN pyrochlores exhibited a layered structure with general formula of CaBi2 Nb2 O9 when the sintering temperature below 1100 °C, and the sample in a nearly pure phase at 1100 °C. The structure of BCN ceramics was gradually transformed into Ca2 Nb2 O7 pyrochlore structure with further increasing the sintering temperature. The dielectric properties varied with structures. The BCN ceramic sintered at 1100 °C exhibited excellent dielectric properties with a dielectric constant of ~ 110 and a dielectric loss of ~ 0.001. The dielectric constants of all the ceramics were independent with the measurement frequency (100 Hz–1 MHz) at room temperature. However, the dielectric loss decreased dramatically at low frequency and then increased slightly with increasing frequency. The temperature dependence of dielectric properties of BCN ceramics was also investigated. The BCN materials with a Ca2 Nb2 O7 pyrochlore structure were more sensitive to the temperature than that with a CaBi2 Nb2 O9 structure. Graphical abstract: