Structure and microwave dielectric properties of La(Mg0.5Ti0.5)O3-CaTiO3 system

(1 - x)La(Mg0.5Ti0.5)O3 (LMT)-xCaTiO3 (CT) [0 < x < 1] ceramics were prepared from powder obtained by a nonconventional chemical route based on the Pechini method. The crystal structure of the microwave dielectric ceramics has been refined by Rietveld method using X-ray powder diffraction data. LMT and CT were found to form a solid solution over the whole compositional range. The 0.9LMT-0.1CT composition was refined using P21/n space group, which allows taking into account B-site ordering. The compounds having x ≥ 0.3 were found to be disordered and were refined using Pbnm space group. Microstructure evolution was also analysed. Dielectric characterization at microwave frequencies was performed on the LMT-CT ceramics. The permittivity and the temperature coefficient of resonant frequency of the solid solutions showed a non-linear variation with composition. The quality factor demonstrates a considerable decrease with the increase of CT content. © 2003 Elsevier Ltd. All rights reserved.