Magnetic properties of γ-Fe2O3 nanoparticles encapsulated in surface-treated polymer spheres

被引：2

作者：

Coaquira, J. A. H. ^{[1
]}

Cardoso, C. A. ^{[2
]}

Soares, F. Q. ^{[3
]}

Garg, V. K. ^{[1
]}

Oliveira, A. C. ^{[1
]}

Rodriguez, A. F. R. ^{[4
]}

Rabelo, D. ^{[3
]}

Morais, P. C. ^{[1
]}

机构：

[1] Univ Brasilia, Inst Fis, Nucleo Fis Aplicada, BR-70910900 Brasilia, DF, Brazil

[2] Univ Fed Sao Carlos, Ctr Ciencias Exatas & Tecnol, Dept Fis, BR-13565905 Sao Paulo, Brazil

[3] Univ Fed Goias, Inst Quim, BR-74001970 Goiania, Go, Brazil

[4] Fundacao Univ Fed Rondonia, Dept Ciencias Exatas & Nat, BR-78961970 Ji Parana, Rondonia, Brazil

来源：

HYPERFINE INTERACTIONS | 2010年 / 195卷 / 1-3期

关键词：

gamma-Fe2O3; nanoparticle; Mossbauer spectroscopy; Magnetization; Core-shell model;

D O I：

10.1007/s10751-009-0112-8

中图分类号：

O64 [物理化学（理论化学）、化学物理学]; O56 [分子物理学、原子物理学];

学科分类号：

070203 ; 070304 ; 081704 ; 1406 ;

摘要：

Mossbauer and magnetic characterization of polymer-dispersed.-Fe2O3 nanoparticles treated under different chemical processes are reported in this work. X-ray powder diffraction analysis provides a mean particle size of D similar to 8.0 nm. Whereas Mossbauer spectroscopy data suggest the presence of only Fe3+ ions, magnetization measurements indicate the occurrence of a freezing phenomenon in agreement with the thermal evolution of Mossbauer spectra. A core-shell model was used to determine a magnetically disordered layer (shell) of d similar to 1.0 nm covering a region of collinear magnetic moments (core). The chemical treatments with H2O2 and Na2S2O8 modify notoriously the magnetic response of the polymer-dispersed nanoparticles.

引用

页码：149 / 154

页数：6

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