Electrical properties of SrBi2(Nb0.7V0.3)2O9−δ in the SrO–Bi2O3–0.7Nb2O5–0.3V2O5–Li2B4O7 glass system

Glasses in the system (100 − x)Li2B4O7–x(SrO–Bi2O3–0.7Nb2O5–0.3V2O5) (where x = 10, 30 and 50, in molar ratio) were fabricated via melt quenching technique. The compositional dependence of the glass transition (Tg) and crystallization (Tcr) temperatures was determined by differential thermal analysis. The as-quenched glasses on heat-treatment at 783 K for 6 h yielded monophasic crystalline strontium bismuth niobate doped with vanadium (SrBi2(Nb0.7V0.3)2O9−δ (SBVN)) in lithium borate (Li2B4O7 (LBO)) glass matrix. The formation of nanocrystalline layered perovskite SBVN phase was preceded by the fluorite phase as established by both the X-ray powder diffraction (XRD) and transmission electron microscopy (TEM). The dielectric constants for both the as-quenched glass and glass–nanocrystal composite increased with increasing temperature in the 300–873 K range, exhibiting a maximum in the vicinity of the crystallization temperature of the host glass matrix. The electrical behavior of the glasses and glass–nanocrystal composites was characterized using impedance spectroscopy.