resumo
The nominal BaTiO3 compound often exhibits an assortment of controversial magnetic signals which can be simply explained through minute presence of spurious magnetic elements in the perovskite matrix, even when this compound is synthesized from high grade Ba and Ti precursors. Proton Induced X-Ray Emission (PIXE) technique enable to confirm similar to 100 ppm of Fe contaminant which masks the utterly BaTiO3 diamagnetism. Nevertheless, besides the expected paramagnetism of highly diluted Fe ions, it is also possible to observe a cooperative magnetic moment signature which exhibits an intricate relation with the phase transitions of the BaTiO3 matrix. Such magneto-electric coupling signature is further corroborated by Raman spectroscopy, dielectric and X-ray diffraction measurements, indicating to a partial segregation of a rich Fe oxide phase, having a local structure clamped to the perovskite crystallites, hence acting as a practical probe sensitive to the local structural transitions of the host material. (C) 2015 Elsevier B.V. All rights reserved.
palavras-chave
PHASE-TRANSITION; FERROMAGNETISM; TEMPERATURE; TITANATE; IONS
categoria
Chemistry; Materials Science; Metallurgy & Metallurgical Engineering
autores
Figueiras, FG; Amorim, CO; Amaral, J; Moreira, JA; Tavares, PB; Alves, E; Amaral, VS
nossos autores
Carlos Amorim
Investigador Auxiliar
Fábio Gabriel Nazário Figueiras
Bolseiro de pós-Doutoramento
João Cunha de Sequeira Amaral
Investigador Auxiliar
Vitor Brás Sequeira Amaral
Professor CatedráticoGrupos
G2 - Materiais Fotónicos, Eletrónicos e Magnéticos
G6 - Materiais Virtuais e Inteligência Artificial
Projectos
CICECO - Aveiro Institute of Materials (UID/CTM/50011/2013)
MULTIFOX: Nanometric Probing and Modification of Multiferroic Oxides (PTDC/FIS/105416/2008)
agradecimentos
This research project has been supported by the European Commission under the 7th Framework Programme through the Key Action: