Structure, Raman spectra, far-infrared spectra and microwave dielectric properties of temperature independent CeVO4-TiO2 composite ceramics

A series of temperature-stable microwave dielectric (1-x)CeVO4-xTiO(2) (0.0 <= x <= 0.4) ceramics were prepared by using solid-state reaction method. All the samples could be sintered well at 1025 degrees C-1150 degrees C for 2 h. X-ray diffraction (XRD) and energy-dispersive spectroscopy (EDS) analysis revealed that rutile TiO2 and tetragonal CeVO4 phases coexisted in the ceramics. Raman spectroscopy and infrared spectra were used to study relationship between structure and microwave dielectric properties. (1-x)CeVO4-xTiO(2) ceramics with 0.15 <= x <= 0.20 sintered at 1100 degrees C for 2 h exhibited good microwave dielectric properties with relative permittivities (epsilon(r)) similar to 11.2-14.2, quality factor (Q x f) values similar to 7950-22,100 GHz (at 9.2-9.5 GHz), and near zero temperature coefficient of resonant frequencies (tau(f)) similar to -1.2 to +2.8 ppm/ degrees C. The infrared spectra study showed that the external vibrations of CeVO4 had the most remarkable effects on the dielectric constant. All these results indicate that this system is a good candidate for microwave devices applications in the future.(C) 2016 Elsevier B.V. All rights reserved.