Study on the structure and dielectric properties of BaO-MgO-Nb2O5-based high-Q ceramic

Ba(Mg1/3Nb2/3)O-3 ceramics were prepared using different amounts of fumed silica, and their crystal structure, phonon mode, and microwave dielectric properties were investigated. The results showed that upon adding 0.16 mol% of magnesium carbonate tetrahydrate and a small amount of fumed silica to the ceramics, the permittivity of the ceramics was greatly reduced compared to that of other Ba(Mg1/3Nb2/3)O-3-based ceramic materials, and the Q x f value was significantly increased. Raman spectra showed that the full width at half maximum values of E-g(Nb) and A(1g)(Nb) were opposite to the variation trends of ordering parameter S and the Q x f values. Optimal dielectric properties, epsilon(r) = 25.17, Q x f = 114,565 GHz (at 6.8 GHz), and tau(f) = 0.82 ppm/degrees C, were achieved for the sample with x = 0.6 wt.% sintered at 1560 degrees C for 10 h.

Automated summary

In this study, Ba(Mg1/3Nb2/3)O-3 ceramics were prepared with the addition of fumed silica and magnesium carbonate tetrahydrate. The results showed that the permittivity of the ceramics was reduced and the Q x f value was increased. Raman spectra demonstrated an opposite trend between crystal widths and ordering parameters as well as Q x f values.