Mechanistics of stabilisation via doping in bismuthsesquioxide $(Bi_{2-2x}Ho_{2x} O_3;x = 0.2)$ A combined approach of Rietveld and microstructural analysis

Sooryanarayana, K and Somashekar, R and Row, Guru TN (1997) Mechanistics of stabilisation via doping in bismuthsesquioxide $(Bi_{2-2x}Ho_{2x} O_3;x = 0.2)$ A combined approach of Rietveld and microstructural analysis. In: Solid State Ionics, 104 (3-4). pp. 319-324.

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Abstract

$\delta-Bi_{1.6} Ho_{0.4} O_3$, is cubic, Fm3m, with a=5.5291(5) \AA, $V=169.03(3) \AA^3$ , $D_{calc} =8.838 g/ cm^3$ , $D_{measured}$ (powder technique)$=8.607 g/cm^3$ , with Z=2. Rietveld profile refinements on high resolution X-ray diffraction data give $R_p = 0.143$, $R_{wp} = 0.188$, $R_{(I,HKL)} = 0.090$, $R_{(expected)}=0.078$ confirming the earlier results on the structure of this phase to have a fluorite type lattice with highly disordered oxygen sublattice. Strain and crystal size analysis of all the reflections in the range $(2\theta = 5-100.94^o)$ from holmium doped bismuth sesquioxide were carried out and compared with the results of the simulated whole powder pattern of $Bi_2 O_3$ for $\alpha$ and $\delta$ phases. These results provide pointers to the possible mechanism of stabilization of $\delta$ phase on holmium substitution.

Item Type:	Journal Article
Publication:	Solid State Ionics
Publisher:	Elsevier
Additional Information:	Copyright of this article belongs to Elsevier.
Keywords:	Bismuth sesquioxide;Holmium stabilized phase;Rietveld refinements;Microstructural parameters
Department/Centre:	Division of Chemical Sciences > Solid State & Structural Chemistry Unit
Date Deposited:	30 May 2007
Last Modified:	19 Sep 2010 04:36
URI:	http://eprints.iisc.ac.in/id/eprint/10381

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