Context
On the formation mechanism of BaTiO3–BaZrO3 solid solution through solid-oxide reaction
Title:
On the formation mechanism of BaTiO3–BaZrO3 solid solution through solid-oxide reaction
Archive:
Dspace@nitr
Author(s):
Bera, J
Rout, S K
Rout, S K
Date:
2005-04-25
Abstract:
Copyright of this article belongs to Elsevier Science Ltd
The formation of solid solution composition BaTi0.6Zr0.4O3, from BaCO3, TiO2 and ZrO2 powders has been studied through solid-oxide reaction using TGA/DSC, XRD. BaCO3 decomposes at much lower temperature in the mixture due to the presence of TiO2. BaTiO3 and BaZrO3 start forming from the temperature range 700o-800oC without intermediate formation of BaO or other titanate/zirconate phases. Rate of BaTiO3 formation is higher than BaZrO3 formation due to the lower activation energy (34.3 kcal/mol) required for titanate formation than zirconate (48.4 kcal/mol). Solid solution then forms by diffusion of BaTiO3 into BaZrO3 from 1300oC onwards. Lattice parameter of initial SS-phase is higher, indicating the phase has a coherent interface with zirconate and higher in Zr-concentration than final product. Activation energy for the SS-formation (133 kcal/mole) indicates that Ba and/or O diffution through SS layer may limit the reaction.
The formation of solid solution composition BaTi0.6Zr0.4O3, from BaCO3, TiO2 and ZrO2 powders has been studied through solid-oxide reaction using TGA/DSC, XRD. BaCO3 decomposes at much lower temperature in the mixture due to the presence of TiO2. BaTiO3 and BaZrO3 start forming from the temperature range 700o-800oC without intermediate formation of BaO or other titanate/zirconate phases. Rate of BaTiO3 formation is higher than BaZrO3 formation due to the lower activation energy (34.3 kcal/mol) required for titanate formation than zirconate (48.4 kcal/mol). Solid solution then forms by diffusion of BaTiO3 into BaZrO3 from 1300oC onwards. Lattice parameter of initial SS-phase is higher, indicating the phase has a coherent interface with zirconate and higher in Zr-concentration than final product. Activation energy for the SS-formation (133 kcal/mole) indicates that Ba and/or O diffution through SS layer may limit the reaction.
Index terms:
Discipline(s):
perovskite
Subject(s):
ferroelectrics; BaTiO3-BaZrO3; solid solution
Method/Approach:
Coverage:
Publisher:
Elsevier
Contributors:
Source:
Language:
en
Relation:
Type:
Article
Format:
897558 bytes
application/pdf
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