Premium
Microstructure and Microwave Dielectric Properties of (1− x )Ca(Mg 1/3 Ta 2/3 )O 3 / x CaTiO 3 Ceramics
Author(s) -
Fu M. S.,
Liu X. Q.,
Chen X. M.,
Zeng Y. W.
Publication year - 2008
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1551-2916.2007.02243.x
Subject(s) - monoclinic crystal system , orthorhombic crystal system , microstructure , dielectric , materials science , analytical chemistry (journal) , temperature coefficient , crystal structure , crystallography , transmission electron microscopy , octahedron , scanning electron microscope , ceramic , solid solution , mineralogy , chemistry , nanotechnology , metallurgy , composite material , optoelectronics , chromatography
Dense (1− x )Ca(Mg 1/3 Ta 2/3 )O 3 / x CaTiO 3 ceramics (0.1≤ x ≤0.9) were prepared by a solid‐state reaction process. The crystal structures and microstructures were characterized by X‐ray diffraction, scanning electron microscopy, and transmission electron microscopy. Single‐phase solid solutions were obtained in the entire composition range. Long‐range 1:2 ordering of B‐site cations and oxygen octahedra tilting lead to the monoclinic symmetry with space group P 2 1 / c for x =0.1. For x above 0.1, the long‐range ordering was destroyed and the crystal structure became the orthorhombic with space group Pbnm . The microwave dielectric properties showed a strong dependence on the composition and microstructure. The dielectric constant and temperature coefficient of resonant frequency increased nonlinearly as the CaTiO 3 content increased while the Qf values decreased approximately linearly. Good combination of microwave dielectric properties was obtained at x =0.45, where ɛ r =45.1, Qf =34 800 GHz, and τ f =17.4 ppm/°C.