Titre:	Core-shell Au/Fe3O4 nanocomposite synthesized by thermal decomposition method : structural, optical, and magnetic properties
Auteur(s):	Oliveira-Filho, G.B. Atoche Medrano, Jason Jerry Aragon, F.F.H. Mantilla Ochoa, J.C. Salazar, D.G. Pacheco Silva, S.W. da Huamaní Coaquira, José Antonio
Assunto::	Nanopartículas Superparamagnetismo Anisotropia
Date de publication:	15-oct-2021
Editeur:	Elsevier
Référence bibliographique:	OLIVEIRA-FILHO, G. B. et al. Core-shell Au/Fe3O4 nanocomposite synthesized by thermal decomposition method: structural, optical, and magnetic properties. Applied Surface Science, v. 563, art. 150290, p. 1-6, out. 2021. DOI 10.1016/j.apsusc.2021.150290. Disponível em: https://doi.org/10.1016/j.apsusc.2021.150290. Acesso em: 04 maio 2022.
Abstract:	Core-shell structure Au@Fe3O4 nanoparticles was synthesized via a thermal decomposition method, evidencing through interplanar atomic distances of ~ 0.23 nm and ~ 0.48 nm finding in the center and the shell of the particles, matching to the (1 1 1) Au and (1 1 1) magnetite planes, respectively. The nanocomposite has an average diameter of the core of ~ 10.5 nm and a thickness of the shell of ~1.85 nm, accessed by TEM. X-ray diffraction carried out on the sample shows the crystal structure of fcc Au and fcc Fe3O4 without a spurious crystalline phase. Besides, Rietveld refinement displays an outer diameter of ~ 8.1 and ~ 12.3 for the core and shell, respectively, the latter using the Scherrer constant of 0.9 and 1.43, respectively. The UV–vis characterization result shows a surface plasmon resonance spectra of Au@Fe3O4 nanoparticles at ~ 540 nm, which advise a successful core–shell coupling of Au and the Fe3O4. Finally, the magnetic response displays a system with a superparamagnetic state at room temperature and with a distribution of blocking temperatures associated with the enhanced surface contribution related to the hollow magnetite structure's inner and outer surface. From the mean TB, the effective magnetic anisotropy J/m3 was obtained, which is in agreement with the expected for the magnetite phase.
DOI:	https://doi.org/10.1016/j.apsusc.2021.150290
metadata.dc.relation.publisherversion:	https://www.sciencedirect.com/science/article/pii/S0169433221013659?via%3Dihub
Collection(s) :	Artigos publicados em periódicos e afins

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