Synthesis and Characterization of Oxide Conductors in Pbo-Bi2o3-M2o5 (M = V, P, As)

Lee, Chiu Sze (2004) Synthesis and Characterization of Oxide Conductors in Pbo-Bi2o3-M2o5 (M = V, P, As). PhD thesis, Universiti Putra Malaysia.

[img] PDF
1724Kb

Abstract

Materials of compositions PbBi6M2O15 and (PbO)n(BiMO4), where M = V, P, As and n = 1, 2, 4 were prepared via solid state reaction. These materials were characterised using X-ray diffraction (XRD), density measurement, inductively coupled plasmaatomic emission spectrometry (ICP-AES), ac impedance spectroscopy, differential thermal analysis (DTA), thermogravimetry analysis (TGA), Fourier-transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). Complete solid solution series were obtained in the PbBi6V2O15-PbBi6P2O15, PbBi6V2O15-PbBi6As2O15 and PbBi6P2O15-PbBi6As2O15 systems. All the materials were isostructural, and crystallised in orthorhombic symmetry. However, the cell parameter a of these materials was twice those reported in JCPDS. The conductivity of these materials decreased in the order of PbBi6V2O15 > PbBi6As2O15 > PbBi6P2O15. PbBi6V2O15 is an oxide ion conductor as it has a transference number of 0.8 above 650ºC. v Substitution of Sr for Pb in PbBi6V2O15 resulted in the formation a new material of SrBi6V2O15 with higher conductivity. On the other hand, Pb in both PbBi6V2O15 and PbBi6As2O15 could be replaced by Na and Bi, resulting in the formation of NaBi13V4O30 and NaBi13As4O30. Besides successfully suppressing the phase transition observed in PbBi6V2O15, these materials had higher conductivity compared to that of PbBi6(V/As)2O15. The conductivity of these materials was in the range of ~ 10-3 ohm-1 cm-1 at 800°C. Conductivity decreased in the order of NaBi13V4O30 > SrBi6V2O15 > PbBi6V2O15. These materials appeared to be oxide ion conductors. Complete solid solution series were formed in the Pb2BiPO6-Pb2BiAsO6, Pb4BiPO8- Pb4BiVO8, Pb4BiPO8-Pb4BiAsO8 and Pb4BiVO8-Pb4BiAsO8 systems. The properties determined generally agreed with those reported; these materials were mixed oxide ion conductors. The conductivity decreased in the order of Pb2BiMO6 > PbBiMO5 > Pb4BiMO8, and V > As > P.

Item Type:Thesis (PhD)
Subject:Oxides.
Chairman Supervisor:Associate Professor Lee Choong Kheng, PhD
Call Number:FSAS 2004 13
Faculty or Institute:Faculty of Environmental Studies
ID Code:62
Deposited By: Khairil Ridzuan Khahirullah
Deposited On:29 Apr 2008 21:28
Last Modified:27 May 2013 06:45

Repository Staff Only: Edit item detail

Document Download Statistics

This item has been downloaded for since 29 Apr 2008 21:28.

View statistics for "Synthesis and Characterization of Oxide Conductors in Pbo-Bi2o3-M2o5 (M = V, P, As)"


Universiti Putra Malaysia Institutional Repository

Universiti Putra Malaysia Institutional Repository is an on-line digital archive that serves as a central collection and storage of scientific information and research at the Universiti Putra Malaysia.

Currently, the collections deposited in the IR consists of Master and PhD theses, Master and PhD Project Report, Journal Articles, Journal Bulletins, Conference Papers, UPM News, Newspaper Cuttings, Patents and Inaugural Lectures.

As the policy of the university does not permit users to view thesis in full text, access is only given to the first 24 pages only.