Effect of two different dopants (Mg2+ and Ca2+) and processing parameters on γ-phase stabilization and conductivity of Bi4V2O11−δ. Issue 8 (September 2015)

• Record Type: Journal Article
• Authors: Gupta, Sakshi; Singh, K.
• Is Part Of: Ceramics international. Volume 41:Issue 8(2015)
• Page Start: 9496
• Page End: 9504
• Publication Date: 2015-09
• Subjects: B. X-ray methods -- Bismuth vanadate -- Defects -- Impedance spectroscopy; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2015.04.007
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: Mg 2+ and Ca 2+ doped Bi4 V2 O11− δ systems are synthesized by a melt quench technique followed by heat treatment. The Ca 2+ doped samples show higher density than Mg 2+ doped samples. All the quenched samples show γ-phase stabilization irrespective of dopants and their concentration. The γ-phase stabilization takes place at lower dopant concentration than earlier reported systems. The conversion of γ-phase to ordered β-phase is observed with heat treatment for Bi4 V2− x Mg x O11− δ ( x =0.05, 0.10 and 0.20) and Bi4 V2− x Ca x O11− δ ( x =0.05 and 0.10). Ca 2+ doped system, particularly high concentration ( x =0.15 and 0.20) did not show γ→γ׳ phase transition. The lowest activation energy; E a is observed for Bi4 Mg0.15 V1.85 O11− δ sample ~0.74 eV in the temperature range 570–750 °C.