Abstract
The structure and microstructure of the Ca1−x(La0.5Na0.5)xWO4 (0.1 ≤ x ≤ 1.0) ceramics were investigated using X-ray powder diffraction (XRD) and scanning electron microscopy (SEM) method. The microwave dielectric properties of the ceramics were studied with a network analyzer at the frequency of about 10–14 GHz. Continuous solid solutions Ca1−x(La0.5Na0.5)xWO4 (0.1 ≤ x ≤ 1.0) with Scheelite structure (space group: I41/a) could be densified at 850 °C/2 h. The dielectric permittivity increased slightly with the increase in substitution amount. The Q × f value decreased with the increase of x up to x = 0.5, and then increased with further increase of x. The Q × f value increased when the sintering temperature increased from 850 to 950 °C for the x 0.5 compositions. The τf value changed a little with the variation of x. All samples exhibited negative τf values. Addition of 30 mol% TiO2 to the x = 0.9 composition improved the τf to −9.3 ppm/°C with er = 14.4 and Q × f = 14,255 GHz after sintering at 850 °C/2 h. The chemical compatibility of Ca0.1(La0.5Na0.5)0.9WO4 + 30 mol% TiO2 composite with silver (Ag) powders was also investigated. The composite showed inert behavior with Ag when cofired at 875 °C for 2 h. However small amount of Na0.86WO3 impurity phase was detected in the co-fired specimen.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Journal of Materials Science: Materials in Electronics
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
