Tuyển tập các báo cáo nghiên cứu khoa học trên tạp chí khoa học vật lý quốc tế đề tài: Mechanochemical Synthesis and Characterisation of Bismuth-Niobium Oxide Ion Conductors | Journal of Physical Science Vol. 20 1 75-86 2009 75 Mechanochemical Synthesis and Characterisation of Bismuth-Niobium Oxide Ion Conductors . Ng . Tan and . Taufiq-Yap Department of Chemistry Faculty of Science Universiti Putra Malaysia 43400 UPM Serdang Selangor Malaysia Corresponding authors sinnee83@ yptan@ Abstract Bismuth niobate solid solutions BixNbO x 6 have been prepared using a mechanochemical method. The solid solutions were also prepared using a solidstate conventional method for comparison purposes. Bi3NbO7 was successfully obtained via a mechanochemical method at a lower synthesis temperature milled at 1000 rpm for one hour followed by heating at 700 C for 24 h than the conventional solid-state method. Electrical properties of the single-phase materials were studied by AC impedance spectroscopy. Further characterization of the materials was carried out using differential thermal analysis DTA and thermogravimetric analysis TGA . The results showed that no thermal changes and phase transitions were observed and all materials were thermally stable. Keywords bismuth niobate mechanochemical solid-state reaction impedance spectroscopy 1. INTRODUCTION Ionic conductors have provided a fascinating interdisciplinary field of study for over a century. In oxygen ion conductors current flow occurs by the movement of an oxide ion through the crystal lattice. As well as the intrinsic interest in these materials there has been a continued drive for their applications in technological devices such as solid oxide fuel cells SOFCs oxygen sensors and many other applications. These entire devices offer the potential of enormous commercial and ecological benefits provided suitable high performance materials can be Yittria-stabilized zirconia YSZ which is used as the electrolyte in SOFC operates at a temperature around 1000oC. Thus high operating temperatures will result in high fabrication costs and also affect the material
