Synthesis of non-stoichiometric $Bi_2O_{4-x}$ by oxidative precipitation

Prakash, AS and Shivakumara, C and Hegde, MS and Dupont, L and Tarascon, JM (2007) Synthesis of non-stoichiometric $Bi_2O_{4-x}$ by oxidative precipitation. In: Materials Research Bulletin, 42 (4). pp. 707-712.

PDF synthesis.pdf Restricted to Registered users only Download (545kB) | Request a copy

Abstract

$Bi_2O_{4-x}$, a Bi mixed-valence phase was prepared at $95 ^0 C$, by a precipitation process, in a basic medium with a highly oxidizing $K_2S_2O_8/Na_2S_2O_8$. This phase has a low thermal stability as it decomposes below $400 ^0 C$ in a multiple step process by some $O_2$ losses prior to finally transforming into $\gamma-Bi_2O_3$. The as-prepared powders are 50–60 nm in size with a narrow size distribution. Optical spectra of $Bi_2O_{4-x}$ exhibit a broad absorption band with a band gap of $\sim 1.4 eV$ as compared to 2.61 eV for $Bi_2O_3$. The composition of this non-stoichiometric phase, which crystallizes in cubic fluorite related structure with a cell parameter of $5.538(3) \AA$, is $Bi_2O_{3.65 \pm 0.10}$.

Item Type:	Journal Article
Publication:	Materials Research Bulletin
Publisher:	Elsevier
Additional Information:	Copyright of this article belongs to Elsevier.
Keywords:	Inorganic compounds;Chemical synthesis;X-ray diffraction;Optical properties
Department/Centre:	Division of Chemical Sciences > Solid State & Structural Chemistry Unit
Date Deposited:	30 May 2008
Last Modified:	19 Sep 2010 04:45
URI:	http://eprints.iisc.ac.in/id/eprint/14127

Actions (login required)

View Item