Nanometric particle size and phase controlled synthesis and characterization of gamma-Fe2O3 or (alpha plus gamma)-Fe2O3 by a modified sol-gel method
Marcela F. Silva, Luiz A. S. de Oliveira, Mariani A. Ciciliati, Lais T. Silva, Bruna S. Pereira, Ana Adelina W. Hechenleitner, Daniela M. F. Oliveira, Kleber R. Pirota, Flávio F. Ivashita, Andrea Paesano Jr., J. Martin Pastor, J. Iñaki Pérez-Landazábal, and Edgardo A. G. Pineda
ARTIGO
Inglês
Agradecimentos: The authors would like to thank Professor Dr. Mauro Baesso and Ms. Gutierrez Rodrigues de Morais for UV-Vis photoacoustic measurements and Professor Dr. Eduardo Radovanovic and David Garcia Ros for TEM micrographs. The authors thank the financial support of Capes-DGU 184-09 and MCI...
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Agradecimentos: The authors would like to thank Professor Dr. Mauro Baesso and Ms. Gutierrez Rodrigues de Morais for UV-Vis photoacoustic measurements and Professor Dr. Eduardo Radovanovic and David Garcia Ros for TEM micrographs. The authors thank the financial support of Capes-DGU 184-09 and MCI Spain-PHB 2008-0044-PC
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Abstract: Fe2O3 nanoparticles with sizes ranging from 15 to 53 nm were synthesized by a modified sol-gel method. Maghemite particles as well as particles with admixture of maghemite and hematite were obtained and characterized by XRD, FTIR, UV-Vis photoacoustic and Mossbauer spectroscopy, TEM, and...
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Abstract: Fe2O3 nanoparticles with sizes ranging from 15 to 53 nm were synthesized by a modified sol-gel method. Maghemite particles as well as particles with admixture of maghemite and hematite were obtained and characterized by XRD, FTIR, UV-Vis photoacoustic and Mossbauer spectroscopy, TEM, and magnetic measurements. The size and hematite/maghemite ratio of the nanoparticles were controlled by changing the Fe:PVA (poly (vinyl alcohol)) monomeric unit ratio used in the medium reaction (1:6, 1:12, 1:18, and 1:24). The average size of the nanoparticles decreases, and the maghemite content increases with increasing PVA amount until 1:18 ratio. The maghemite and hematite nanoparticles showed cubic and hexagonal morphology, respectively. Direct band gap energy were 1.77 and 1.91 eV for A6 and A18 samples. Zero-field-cooling-field-cooling curves show that samples present superparamagnetic behavior. Maghemite-hematite phase transition and hematite Neel transition were observed near 700K and 1015 K, respectively. Magnetization of the particles increases consistently with the increase in the amount of PVA used in the synthesis. Mossbauer spectra were adjusted with a hematite sextet and maghemite distribution for A6, A12, and A24 and with maghemite distribution for A18, in agreement with XRD results
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COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPES
184-09
Fechado
DOI: https://doi.org/10.1063/1.4821253
Texto completo: https://aip.scitation.org/doi/10.1063/1.4821253
Nanometric particle size and phase controlled synthesis and characterization of gamma-Fe2O3 or (alpha plus gamma)-Fe2O3 by a modified sol-gel method
Marcela F. Silva, Luiz A. S. de Oliveira, Mariani A. Ciciliati, Lais T. Silva, Bruna S. Pereira, Ana Adelina W. Hechenleitner, Daniela M. F. Oliveira, Kleber R. Pirota, Flávio F. Ivashita, Andrea Paesano Jr., J. Martin Pastor, J. Iñaki Pérez-Landazábal, and Edgardo A. G. Pineda
Nanometric particle size and phase controlled synthesis and characterization of gamma-Fe2O3 or (alpha plus gamma)-Fe2O3 by a modified sol-gel method
Marcela F. Silva, Luiz A. S. de Oliveira, Mariani A. Ciciliati, Lais T. Silva, Bruna S. Pereira, Ana Adelina W. Hechenleitner, Daniela M. F. Oliveira, Kleber R. Pirota, Flávio F. Ivashita, Andrea Paesano Jr., J. Martin Pastor, J. Iñaki Pérez-Landazábal, and Edgardo A. G. Pineda
Fontes
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Journal of applied physics Vol. 114, n. 10 (Sept., 2013), n. art. 104311, p. 1-7 |