De-sintering of Ba5Nb4O15 ceramic and its influence on microwave characteristics. Issue 4 (April 2017)

• Record Type: Journal Article
• Authors: Tsao, Chung-Ya; Tuan, Wei-Hsing; Feng, Kuei-Chih
• Is Part Of: Journal of the European Ceramic Society. Volume 37:Issue 4(2017)
• Page Start: 1517
• Page End: 1521
• Publication Date: 2017-04
• Subjects: Microwave -- Sintering -- Ba5Nb4O15 -- Grain growth -- Crystal structure; Ceramic materials -- Periodicals; Composite materials -- Periodicals; Matériaux céramiques -- Périodiques; Composites -- Périodiques; Ceramic materials; Composite materials; Periodicals; Electronic journals; 666.05
• DOI: 10.1016/j.jeurceramsoc.2016.11.002
• Languages: English
• ISSNs: 0955-2219

Abstract

Abstract: The sintering behaviour of a cation-deficient perovskite, Ba5 Nb4 O15, is investigated in the present study. The highest density can be achieved through pressureless sintering at 1250 °C is only 93%. A further increase in sintering temperature results in a decrease in density; for example, the density is only 82% after sintering at 1435 °C. The density decrease, de-sintering, can be related to the formation of abnormal grains ( > 1250 °C) and the reduction of niobium ions ( > 1400 °C). The permittivity of sintered Ba5 Nb4 O15 specimen shows strong dependence on density; however, the quality factor ( Qxf ) increases to 45, 000 with the increase of sintering temperature. The increase in quality factor is attributed to the ordering of cations in the perovskite structure.