Size selected synthesis of CoFe{sub 2}O{sub 4} nanoparticles prepared in a chitosan matrix

Journal Article · Sat May 15 00:00:00 EDT 2010 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3339784· OSTI ID:21476209

Gurgel, A L; Soares, J M; Chaves, D S ^[1]; Xavier, Jr, M M; Morales, M A ^[2]; Baggio-Saitovitch, E M ^[3]; Chaves, D S

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1. Departamento de Fisica, Universidade do Estado do Rio Grande do Norte, UERN, Mossoro, RN 59610-090 (Brazil)
2. Departamento de Ciencias Exatas e Naturais, Universidade Federal Rural do Semi-Arido, UFERSA, Mossoro, RN 59625-900 (Brazil)
3. Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ 22290-180 (Brazil)

In this paper we report the synthesis and magnetic properties of CoFe{sub 2}O{sub 4} nanoparticles. The nanoparticles with sizes ranging from 6 to 20 nm were prepared in a chitosan matrix. Size selection was achieved by introducing a nonionic surfactant Tween-X, where X={l_brace}20, 60, 80, and 85{r_brace}. Aqueous dispersions of Tween-X show micelles with increasing hydrodynamic sizes as X increases. Moessbauer spectroscopy measurements at 300 K show superparamagnetic behavior for the small particles, changing gradually to a blocked magnetic regime as the particle size increases. Magnetization measurements at 300 K show increasing values for the ratio M{sub r}/M{sub Hmax} and coercive fields (H{sub c}).

• OSTI ID: 21476209
• Journal Information: Journal of Applied Physics, Vol. 107, Issue 9; Conference: 11. joint MMM-Intermag conference, Washington, DC (United States), 18-22 Jan 2010; Other Information: DOI: 10.1063/1.3339784; (c) 2010 American Institute of Physics; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
77 NANOSCIENCE AND NANOTECHNOLOGY
AMINO ACIDS
COBALT OXIDES
COERCIVE FORCE
FERRITES
HYDRODYNAMICS
MAGNETIC PROPERTIES
MAGNETIZATION
MATRIX MATERIALS
MOESSBAUER EFFECT
NANOSTRUCTURES
OLIGOSACCHARIDES
PARTICLE SIZE
PARTICLES
SUPERPARAMAGNETISM
SYNTHESIS
CARBOHYDRATES
CARBOXYLIC ACIDS
CHALCOGENIDES
COBALT COMPOUNDS
FERRIMAGNETIC MATERIALS
FLUID MECHANICS
IRON COMPOUNDS
MAGNETIC MATERIALS
MAGNETISM
MATERIALS
MECHANICS
ORGANIC ACIDS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
SACCHARIDES
SIZE
TRANSITION ELEMENT COMPOUNDS