Effects of Sr2+ substitution on the crystal structure, Raman spectra, bond valence and microwave dielectric properties of Ba3-xSrx(VO4)2 solid solutions

The effects of Sr2+ substitution for Ba2+ on microwave dielectric properties and crystal structure of Ba3-xSrx(VO4)(2) (0 <= x <= 3, BSVO) solid solution were investigated. Such Sr2+ substitution contributes to significant reduction in sintering temperature from 1400 degrees C to 1150 degrees C. Both permittivity (Sigma(r)) and quality factor (Q x f) values decreased with increasing x value, which was determined to be related with the descending values of average polarizability and packing fraction, whereas the increase in tau(f) value was explained by the decreased average V-O bond length, A-site bond valence. BSVO ceramics possessed encouraging dielectric performances with Sigma(r) = 12.2-15.6 +/- 0.1, Q x f = 44,340 - 62,000 +/- 800 GHz, and tau(f) = 24.5-64.5 +/- 0.2 ppm/degrees C. Low-temperature sintering was manipulated by adding B2O3 as sintering additive for the representative Sr3V2O8 (SVO) ceramic and only 1 wt.% B2O3 addition successfully contributed to a 21.7% decrease in sintering temperature to 900 degrees C, showing good chemical compatibility with silver electrodes, which render BSVO series and SVO ceramics potential candidates in multilayer electronic devices fabrication.