High Q ceramics in the ACe2(MoO4)4 (A=Ba, Sr and Ca) system for LTCC applications

• Published in: Journal of alloys and compounds 2013-02, Vol.550, p.169-172
• Main Authors: Surjith, A., Ratheesh, R.
• Format: Article
• Language: English
• Subjects: Cations; Ceramics; Coefficients; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Dielectric properties; Dielectric properties of solids and liquids; Dielectrics, piezoelectrics, and ferroelectrics and their properties; Exact sciences and technology; Microwaves; Permittivity (dielectric function); Physics; Quality factor; Resonant frequencies; Scanning electron microscopy; Solid state reactions; Strontium; X-ray diffraction
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2012.09.055

► Solid state synthesis of phase pure ACe2(MoO4)4 (A=Ba, Sr and Ca) ceramics. ► Structural and microstructural evaluation of the synthesized ceramic materials. ► Microwave dielectric property studies of ACe2(MoO4)4 (A=Ba, Sr and Ca) ceramics. ► Structure-property correlation through Laser Raman studies. Novel low temperature sinterable high Q ceramic systems ACe2(MoO4)4 (A=Ba, Sr and Ca) have been prepared through solid state ceramic method. The effect of ionic radii of alkaline earth cations on the structure, microstructure and microwave dielectric properties of these ceramics were studied using powder X-ray diffraction, Laser Raman spectroscopy, scanning electron microscopy and Vector Network Analyzer. A structural change from monoclinic to tetragonal structure was observed while substituting Sr2+ and Ca2+ cations in place of Ba2+. The Sr and Ca analogues possess better microwave dielectric properties compared to BaCe2(MoO4)4. All the ceramics were well sintered below 840°C with dielectric constant in the range 10.2–12.3 together with good quality factor. The SrCe2(MoO4)4 ceramic exhibits an unloaded quality factor of 6762 at 8.080662GHz with a temperature coefficient of resonant frequency of −46ppm/°C while the CaCe2(MoO4)4 ceramic shows an unloaded quality factor of 7549 at 6.928868GHz and a temperature coefficient of resonant frequency of −44ppm/°C.