Microwave dielectric properties of (1-x)CeO2-xCaTiO3 and (1-x)CeO2-xSm2O3 ceramics

• Published in: Journal of the European Ceramic Society Vol. 24; no. 9; pp. 2583 - 2589
• Main Authors: SEBASTIAN, M. T, SANTHA, N, BIJUMON, P. V, AXELSSON, Anna-Karin, ALFORD, Neil Mcn
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier 01.08.2004
• 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; Samarium oxides; Scanning electron microscopy; Dielectric resonator; Q factor; Electrical properties; Dielectric properties; Calcium Titanates; Microwave; Cerium oxide; Experimental study; Solid solution; X ray diffraction; Oxide ceramics; Dielectric ceramics; Lanthanide compound; Characterization; Temperature coefficient; Solid state reaction; Manufacturing; Permittivity; Raman spectrum; Electroceramics
• ISSN: 0955-2219; 1873-619X
• DOI: 10.1016/j.jeurceramsoc.2003.09.027

CeO2-CaTiO3 and CeO2-Sm2O3 microwave dielectric ceramics were prepared by a conventional solid state ceramic route. The dielectric ceramics were characterised by XRD, SEM, Raman and microwave methods. Ceria has a relative dielectric constant, epsilon r, of 23, high dielectric quality factorxfrequency product, Qxf up to 60000 GHz with high temperature coefficient of resonant frequency, tau f, of -53 ppm/C. The addition of CaTiO3 and Sm2O3 leads to a zero temperature variation of resonant frequency. The relative dielectric constant increases and Q decreases with CaTiO3 addition and the tau f changes from a negative to a positive value. Sm2O3 addition of up to 50 mol% increases Q, decreases epsilon r and improves the tau f. The microwave dielectric properties are measured at low temperatures down to 20 K. The effect of addition of 1 mol% of various rare earth oxides on the microwave dielectric properties of ceria was also investigated. 14 refs.