Microwave dielectric properties of (1− x)CeO 2– xCaTiO 3 and (1− x)CeO 2– xSm 2O 3 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: Elsevier Ltd 2004
• Subjects: CaTiO 3; CeO 2; Dielectric resonators; Microwave ceramics; Sm 2O 3; CeO 2; Sm 2O 3; CaTiO 3; Dielectric resonators; Microwave ceramics
• ISSN: 0955-2219; 1873-619X
• DOI: 10.1016/j.jeurceramsoc.2003.09.027

CeO 2–CaTiO 3 and CeO 2–Sm 2O 3 microwave dielectric ceramics have been prepared by a conventional solid state ceramic route. The dielectric ceramics are characterized by X-ray diffraction, SEM, Raman and microwave methods. Ceria has a relative dielectric constant, ε r, of 23, high dielectric quality factor×frequency product, Q× f up to 60,000 GHz with high temperature coefficient of resonant frequency, τ f, of −53 ppm/°C. The addition of CaTiO 3 and samarium oxide leads to a zero temperature variation of resonant frequency. The relative dielectric constant increases and Q decrease with CaTiO 3 addition and the τ r changes from a negative to a positive value. Sm 2O 3 addition of up to 50 mol% increases Q, decreases ε r and improves the τ 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 has also been investigated.