Effects of microstructure on the microwave dielectric properties of Ba(Co1/3Nb2/3)O3 and (1-x)Ba(Co1/3Nb2/3)O3-xBa(Zn1/3Nb2/3)O3 ceramics

• Published in: Journal of the European Ceramic Society Vol. 23; no. 14; pp. 2473 - 2478
• Main Authors: AHN, Cheol-Woo, JANG, Hyun-Jung, NAHM, Sahn, PARK, Hyun-Min, LEE, Hwack-Joo
• Format: Conference Proceeding Journal Article
• Language: English
• Published: Oxford Elsevier 2003
• Subjects: Applied sciences; Building materials. Ceramics. Glasses; Ceramic industries; Chemical industry and chemicals; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Dielectric properties of solids and liquids; Dielectrics, piezoelectrics, and ferroelectrics and their properties; Electrotechnical and electronic ceramics; Exact sciences and technology; Permittivity (dielectric function); Physics; Technical ceramics; Scanning electron microscopy; Dielectric loss; Cobalt Oxides; Perovskite type compound; Electrical properties; Dielectric properties; Ordered structure; Barium Cobalt Niobium Oxides Mixed; Zinc Oxides; Liquid phase sintering; Experimental study; X ray diffraction; Oxide ceramics; Hexagonal lattices; Barium Oxides; Niobium Oxides; Fabrication structure relation; Property structure relationship; Manufacturing; Microstructure; Barium Niobium Zinc Oxides Mixed; Electroceramics
• ISSN: 0955-2219; 1873-619X
• DOI: 10.1016/s0955-2219(03)00151-1

Ba(Co1/3Nb2/3)O3 (BCN) has a 1:2 ordered hexagonal structure. A large amount of the liquid phase, which contains high concentrations of Ba and Nb ions was found in the BCN ceramics. Q-values of BCN increased with increasing sintering temperature; however, they significantly decreased when the sintering temperature exceeded 1400 C. The presence of a large amount of liquid phase could be responsible for this decrease. For (1-x)Ba(Co1/3Nb2/3)O3-xBa(Zn1 /3Nb2/3)O3 [(1-x)BCN-xBZN] ceramics, the 1:2 ordered hexagonal structure was seen in specimens with x up to 0.3 and the BaNb6O16 second phase was found in the specimens with x = 0.6 and above. Grain growth, which is related to the BaNb6O16 second phase, occurred in the specimens with x = 0.5 and above. In this work, the excellent microwave dielectric properties of tauf = 0.0 ppm/C, epsilonr = 34.5 and Qf = 97000 GHz were obtained for the 0.7BCN-0.3BZN ceramics sintered at 1400 C for 20 h. 10 refs.