Influence of Yb-doping on structural, dielectric and electrical properties of SrBi2Nb2O9 ceramics prepared through the molten-salt method

The precursors were mediated by transient eutectic salt, at 46 wt% NaNO 3 –54 wt% KNO 3 , in situ melted by moderate mechanical agitation to form colloidal suspension oxides dispersed in liquefied NaNO 3 –KNO 3 salt. FTIR transmittance bands detected between 440 and 805 cm −1 are the characteristic bands of SrBi 2 Nb 2 O 9 arising from the NbO 6 octahedra. The XRD technique revealed that the expected products proceeded in an optimum calcination condition and a single phase was obtained without secondary phases. Yb-doped SrBi 2 Nb 2 O 9 compounds exhibit strong absorption bands below 400 nm, with an onset in the visible region at 700 nm. The effect of dopants on morphology has not been seen through the SEM technique. The magnitude of the dielectric constant is mainly correlated to the intrinsic polarizability of bismuth. As a result, the addition of a small amount of Yb decreases the dielectric constant of SrBi 2 Nb 2 O 9 ceramics. Meanwhile, doping with Yb was used to demonstrate the decrease in dielectric loss either by inhibiting the transport of charge carriers or by enhancing ceramic density. The increase in ac conductivity as the temperature increases indicates the samples exhibit a negative temperature coefficient of resistance property.