Local structure and hybridization states in Ba0.9Ca0.1Ti1-xZrxO3 ceramic compounds: Correlation with a normal or relaxor ferroelectric character

Autor(es)

Mastelaro, V. R. ^[1] ; Favarim, H. R. ^[2] ; Mesquita, A. ^[3] ; Michalowicz, A. ^{[4, 5]} ; Moscovici, J. ^{[4, 5]} ; Eiras, J. A. ^[6]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Fis Sao Carlos, Sao Carlos, SP - Brazil

^[2] Univ Fed Ouro Preto, DEFIS, Ouro Preto, MG - Brazil

^[3] Univ Estadual Paulista, Dept Fis, Inst Geociencias & Ciencias Exatas, Rio Claro, SP - Brazil

^[4] CNRS, Inst Chim & Mat Paris Est, F-94320 Thiais - France

^[5] Univ Paris Est Creteil, F-94320 Thiais - France

^[6] Univ Fed Sao Carlos, Dept Fis, BR-13560 Sao Carlos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: ACTA MATERIALIA; v. 84, p. 164-171, FEB 1 2015.
• Citações Web of Science: 22

Resumo

This paper reports on a multi-edge X-ray absorption analysis to elucidate how the substitution of Ti4+ by Zr4+ ions acts on the local order structure and on the O 2p hybridization states of Ba0.9Ca0.1Ti1-xZrxO3 (BCZT) lead-free ceramic compounds, inducing a ferroelectric evolution from a normal to a relaxor character. Ti, Ba, Zr and 0 X-ray absorption spectra were measured to probe the local and electronic structure of BCZT samples that exhibit a normal (x < 0.18) or relaxor (x >= 0.18) ferroelectric character. X-ray absorption near edge structure results show that the local symmetry and distortion of TiO6, ZrO6 and BaO12 units are not significantly affected by the Ti/Zr ratio, the ferroelectric character or the long-range order symmetry. The assignment of the ab initio density of states associated with the O K-edge enabled a correlation between the decrease in the hybridization between O 2p and Ti 3d states and the ferroelectric character evolution of the BCZT samples. The hybridization states in the ferroelectric relaxor samples exhibit a more symmetric spatial configuration, as occurs with long-range symmetry. (C) 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. (AU)

• Processo FAPESP: 08/04025-0 - Materiais multifuncionais multiferróicos nanoestruturados: síntese, propriedades, fenomenologia e aplicações
• Beneficiário: José Antonio Eiras
• Modalidade de apoio: Auxílio à Pesquisa - Temático