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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Tuning dipolar magnetic interactions by controlling individual silica coating of iron oxide nanoparticles

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Author(s):
Rivas Rojas, P. C. [1] ; Tancredi, P. [1] ; Moscoso Londono, O. [2, 3] ; Knobel, M. [2] ; Socolovsky, L. M. [1]
Total Authors: 5
Affiliation:
[1] Univ Buenos Aires, CONICET, Fac Ingn, Lab Solidos Amorfos, Inst Tecnol & Ciencias Ingn Hilario Fernandez Lon, Buenos Aires, DF - Argentina
[2] Univ Estadual Campinas, Inst Fis Gleb Wataghin, Lab Mat & Baixas Temp, Campinas, SP - Brazil
[3] Univ Autonoma Manizales, Antigua Estn Ferrocarril, Manizales - Colombia
Total Affiliations: 3
Document type: Journal article
Source: Journal of Magnetism and Magnetic Materials; v. 451, p. 688-696, APR 1 2018.
Web of Science Citations: 6
Abstract

Single and fixed size core, core-shell nanoparticles of iron oxides coated with a silica layer of tunable thickness were prepared by chemical routes, aiming to generate a frame of study of magnetic nanoparticles with controlled dipolar interactions. The batch of iron oxides nanoparticles of 4.5 nm radii, were employed as cores for all the coated samples. The latter was obtained via thermal decomposition of organic precursors, resulting on nanoparticles covered with an organic layer that was subsequently used to promote the ligand exchange in the inverse microemulsion process, employed to coat each nanoparticle with silica. The amount of precursor and times of reaction was varied to obtain different silica shell thicknesses, ranging from 0.5 nm to 19 nm. The formation of the desired structures was corroborated by TEM and SAXS measurements, the core single-phase spinel structure was confirmed by XRD, and superparamagnetic features with gradual change related to dipolar interaction effects were obtained by the study of the applied field and temperature dependence of the magnetization. To illustrate that dipolar interactions are consistently controlled, the main magnetic properties are presented and analyzed as a function of center to center minimum distance between the magnetic cores. (C) 2017 Elsevier B.V. All rights reserved. (AU)

FAPESP's process: 14/26672-8 - Interface and surface effects in magnetic-metal nanoheterostructures
Grantee:Oscar Moscoso Londono
Support Opportunities: Scholarships in Brazil - Post-Doctoral