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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.)

Formation Mechanism via a Heterocoagulation Approach of FePt Nanoparticles Using the Modified Polyol Process

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Author(s):
Beck, Jr., Watson [1] ; Souza, Caio G. S. [1] ; Silva, Tiago L. [1] ; Jafelicci, Jr., Miguel [2] ; Varanda, Laudemir C. [1]
Total Authors: 5
Affiliation:
[1] Univ Sao Paulo USP, Inst Quim Sao Carlos, Colloidal Mat Grp, BR-13566590 Sao Carlos, SP - Brazil
[2] Univ Estadual Paulista UNESP, Inst Quim Araraquara, Dept Quim Fis, Araraquara, SP - Brazil
Total Affiliations: 2
Document type: Journal article
Source: Journal of Physical Chemistry C; v. 115, n. 21, p. 10475-10482, JUN 2 2011.
Web of Science Citations: 24
Abstract

Herein, we report a new approach of an FePt nanoparticle formation mechanism studying the evolution of particle size and composition during the synthesis using the modified polyol process. One of the factors limiting their application in ultra-high-density magnetic storage media is the particle-to-particle composition, which affects the A1-to-L1(0) transformation as well as their magnetic properties. There are many controversies in the literature concerning the mechanism of the FePt formation, which seems to be the key to understanding the compositional chemical distribution. Our results convincingly show that, initially, Pt nuclei are formed due to reduction of Pt(acac)(2) by the diol, followed by heterocoagulation of Fe cluster species formed from Fe(acac)(3) thermal decomposition onto the Pt nuclei. Complete reduction of heterocoagulated iron species seems to involve a CO-spillover process, in which the Pt nuclei surface acts as a heterogeneous catalyst, leading to the improvement of the single-particle composition control and allowing a much narrower compositional distribution. Our results show significant decreases in the particle-to-particle composition range, improving the A1-to-L1(0) phase transformation and, consequently, the magnetic properties when compared with other reported methods. (AU)

FAPESP's process: 08/07568-4 - FePt-based magnetic nanorods: synthesis, characterization, and self-assembling for ultrahigh-density magnetic recording application.
Grantee:Tiago Luis da Silva
Support Opportunities: Scholarships in Brazil - Master
FAPESP's process: 07/07919-9 - Colloidal magnetic nanocrystals: synthesis of self-assembled and macromolecules-functionalised nanospheres, nanowires, and nanorods for advanced magnetic recording, biotechnological, and biomedical applications
Grantee:Laudemir Carlos Varanda
Support Opportunities: Research Grants - Young Investigators Grants
FAPESP's process: 08/08791-9 - Iron oxide-coated metallic magnetic nanoparticles: improvement of the nanoparticle magnetic properties and functionalization for biomedical applications.
Grantee:Watson Beck Junior
Support Opportunities: Scholarships in Brazil - Master