Electrical properties of SrBi2(Nb0.7V0.3)2O9-δ in the SrO-Bi2O3-.7Nb2O5-0.3V2O5-LiB4O7 glass system

Glasses in the system (100 - x)Li2B4O7-x(SrO-Bi2O3-0.7Nb(2)O(5)-0.3V(2)O(5)) (where x = 10, 30 and 50, in molar ratio) were fabricated via melt quenching technique. The compositional dependence of the glass transition (T-g) and crystallization (T-cr) 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)(2)O9-delta (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. (c) 2006 Elsevier B.V. All rights reserved.