Influence of liquid phase lead borate glass on dielectric response of lead iron niobate

Lead iron niobate PbFe1/2+3Nb1/2+5O3 (PFN) is well recognized lead-based complex-double perovskite [A(BIBII)O3] ferroelectrics. In the present work, the influence of liquid phase of lead borate glass 4PbO-B2O3 (LB) on sinterability and dielectric behaviours of PFN are systematically investigated. The PFN powder was synthesized by combustion route (SHS synthesis) and LB-glass by conventional quenching technique, separately. The compositions of PFN and LB-glass (0-3 wt%) were prepared by ball milling. The crystalline structure of as-synthesized PFN, PFN-LB and amorphous nature of LB-glass are confirmed by XRD and well fitted by Rietveld refinement with monoclinic structure of 'Cm' space group. Microstructure was examined by SEM and TEM; indicates nanoscale dimensions of as-synthesized PFN. The green pellets of PFN and PFN-LB were sintered at various sintering conditions. Liquid phase sintering by LB-glass in PFN is found to strongly influence on the morphology, compactness and dielectric behaviour of nanostructure PFN. Semiquantitative correlation between microstructure and dielectric behaviour was established.