resumo
We report the synthesis, structural and ferroelectric characterization of continuous well-aligned nanofibres of barium titanate produced by the electrospinning technique. The fibres with average diameter of 150-400 nm consist of connected nanoparticles of BaTiO3 stacked together to form the shape of a long filament. The tetragonal phase in the obtained nanofibres was revealed by the x-ray diffraction and Raman spectroscopy and has been also confirmed by the second harmonic generation (SHG) and piezoresponse force microscopy (PFM). The temperature dependence of the SHG in the vicinity of the paraelectric-ferroelectric phase transition suggests that barium titanate nanofibres are indeed ferroelectric with an apparent glass-like state caused by metastable polar nanoregions. The existence of domain structure and local switching studied by PFM present clear evidence of the polar phase at room temperature.
palavras-chave
PHASE-TRANSITIONS; 2ND-HARMONIC GENERATION; NANOCRYSTALLINE BATIO3; THIN-FILMS; CERAMICS; RAMAN
categoria
Physics
autores
Sa, P; Barbosa, J; Bdikin, I; Almeida, B; Rolo, AG; Gomes, ED; Belsley, M; Kholkin, AL; Isakov, D
nossos autores
Andrei Kholkin
Investigador JubiladoProjectos
Multiferroics and magnetoelectrics for spintronics: barriers and interfaces (PTDC/CTM/099415/2008)
agradecimentos
This work has been done in the framework of the CIENCIA-2007 programme (reference UMINHO-CF-06) and was financially supported by the European Regional Development Fund (ERDF) through Programa Operacional Factores de Competitividade (COMPETE: FCOMP-01-0124-FEDER-014628), by the Portuguese Foundation for Science and Technology (FCT) (PTDC/CTM-NAN/114269/2009, PTDC/CTM-NAN/115125/2009, PTDC/CTM-CER/115085/2009, PTDC/CTM/105597/2008, PTDC/CTM/099415/2008) and by the strategic project PEST-C/FIS/UI607/2011.