Characterization of dense lead lanthanum titanate ceramics prepared from powders synthesized by the oxidant peroxo method
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Data
2010-12-01
Autores
Pinto, Alexandre H.
Souza, Flavio L.
Chiquito, Adenilson J.
Longo, Elson [UNESP]
Leite, Edson R.
Camargo, Emerson R.
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Editor
Elsevier B.V. Sa
Resumo
Nanosized powders of lead lanthanum titanate (Pb(1-x)La(x)TiO(3)) were synthesized by means of the oxidant-peroxo method (OPM) Lanthanum was added from 5 to 30% in mol through the dissolution of lanthanum oxide in nitric acid followed by the addition of lead nitrate to prepare a solution of lead and lanthanum nitrates which was dripped into an aqueous solution of titanium peroxo complexes forming a reactive amorphous precipitate that could be crystallized by heat treatment Crystallized powders were characterized by FT-Raman spectroscopy and X-ray powder diffraction showing that tetragonal perovskite structure is obtained for samples up to 25% of lanthanum and cubic perovskite for samples with 30% of lanthanum Powders containing 25 and 30% in mol of lanthanum were calcined at 700 degrees C for 2 h and in order to determine the relative dielectric permittivity and the phase transition behaviour from ferroelectric-to-paraelectric ceramic pellets were prepared and sintered at 1100 or 1150 degrees C for 2 h and subjected to electrical characterization It was possible to observe that sample containing 25% in mol of La presented a normal behaviour for the phase transition whereas the sample containing 30% in mol of La presented a diffuse phase transition and relaxor behaviour (C) 2010 Elsevier B V All rights reserved
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Oxides, Chemical synthesis, Crystal structures, Dielectric properties
Como citar
Materials Chemistry and Physics. Lausanne: Elsevier B.V. Sa, v. 124, n. 2-3, p. 1051-1056, 2010.