Observation of very high dielectric constant in Sr(Fe<inf>1-x</inf>Al<inf>x</inf>)<inf>0.5</inf>Nb<inf>0.5</inf>O<inf>3</inf> ceramics prepared by molten salt technique

• Main Authors: Thanatep Phatungthane, Gobwute Rujijanagul
• Format: Journal
• Published: 2018
• Subjects: Agricultural and Biological Sciences
• Online Access: https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84937514190&origin=inward; http://cmuir.cmu.ac.th/jspui/handle/6653943832/44429
• Institution: Chiang Mai University

© 2015 Elsevier Ltd and Techna Group S.r.l. All rights reserved. Sr(Fe < inf > 1-x < /inf > Al < inf > x < /inf > ) < inf > 0.5 < /inf > Nb < inf > 0.5 < /inf > O < inf > 3 < /inf > (x≠& 0.20) powders were synthesized via the molten-sals process. Pure phase perovskite was obtained at a relatively low calcination temperature of 800 °C. The Sr(Fe;bsubesubbsubesubbsubesubbsubesubbsubesub & ceramics exhibited pure phase perovskite for x < 0.20 ceramics. Dielectric measurements indicated that all ceramics showed a strong dielectric frequency dispersion, especially for the x=0.05 ceramic. Very high dielectric constants (ε > 199,000 for temperatures > 200 °C) were observed for the x=0.05 ceramics. Al doping enhanced the dielectric temperature stability and reduced the loss tangent. Impedance spectroscopic analysis indicated that the dielectric behaviour of the ceramics could be related to the Maxwell-Wagner polarization mechanism, since the ceramics exhibited heterogeneous conduction.