Microwave dielectric properties of (Bi1 − xRx)NbO4 ceramics (R = Ce,Nd,Dy,Er)

(Bi1 − xRx)NbO4 (R = Ce,Nd,Dy,Er; x = 0.03 mol) ceramics with 0.1 wt.% CuO + V2O5 as a sintering aid were prepared by conventional solid state reaction process. The microwave dielectric properties of (Bi1 − xRx)NbO4 ceramics were investigated as a functional of R ions. The microwave dielectric properties such as dielectric constant, Q value and temperature coefficient of resonant frequency (TCF) are found to correlate with the R ions. When R = Ce, the dielectric constant, Q value and TCF are 44.7, 5000 and −4.9 ppm/°C, respectively at about 5 GHz. The relation of microwave dielectric properties and the ionic radii, polarizability and bond valence of R (R = Ce, Nd, Dy, Er) was discussed. The Q value decreased with decreasing the bond valence and the size of R ions. The dielectric constant decreased with decreasing polarizability.