Influence of heavy rare earth ions substitution on microstructure and magnetism of nanocrystalline magnetite


Autoria(s): CVEJIC, Z.; ANTIC, B.; KREMENOVIC, A.; RAKIC, S.; Goya, Gerardo Fabian; Rechenberg, Hercilio Rodolfo; JOVALEKIC, C.; SPASOJEVIC, V.
Contribuinte(s)

UNIVERSIDADE DE SÃO PAULO

Data(s)

20/10/2012

20/10/2012

2009

Resumo

In this work we report results on the influence of heavy rare earth ions substitution on microstructure and magnetism of nanocrystalline magnetite. A series of Fe(2.85)RE(0.15)O(4) (RE = Gd, Dy, Ho, Tm and Yb) samples have been prepared by high energy ball milling. Structure/microstructure investigations of two selected samples Fe(2.85)Gd(0.15)O(4) and Fe(2.85)Tm(0.15)O(4), represent an extension of the previously published results on Fe(3)O(4)/gamma-Fe(2)O(3), Fe(2.85)Y(0.15)O(4) and Fe(2.55)In(0.45)O(4) [Z. Cvejic, S. Rakic, A. Kremenovic, B. Antic, C. Jovalekic. Ph. Colomban, Sol. State Sciences 8 (2006) 908], while magnetic characterization has been done for all the samples. Crystallite/particle size and strain determined by X-ray diffractometry and Transmission electron microscopy (TEM) confirmed the nanostructured nature of the mechanosynthesized materials. X-ray powder diffraction was used to analyze anisotropic line broadening effects through the Rietveld method. The size anisotropy was found to be small while strain anisotropy was large, indicating nonuniform distribution of deffects in the presence of Gd and Tm in the crystal structure. Superparamagnetic(SPM) behavior at room temperature was observed for all samples studied. The Y-substituted Fe(3)O(4) had the largest He and the lowest M(S). We discuss the changes in magnetic properties in relation to their magnetic anisotropy and microstructure. High field irreversibility (H>20kOe) in ZFC/FC magnetization versus temperature indicates the existence of high magnetocrystalline and/or strain induced anisotropy. (C) 2008 Elsevier B.V. All rights reserved.

Serbian Ministry of Science

Serbian Ministry of Science and Environmental Protection

Identificador

JOURNAL OF ALLOYS AND COMPOUNDS, v.472, n.1/Fev, p.571-575, 2009

0925-8388

http://producao.usp.br/handle/BDPI/29405

10.1016/j.jallcom.2008.05.026

http://dx.doi.org/10.1016/j.jallcom.2008.05.026

Idioma(s)

eng

Publicador

ELSEVIER SCIENCE SA

Relação

Journal of Alloys and Compounds

Direitos

restrictedAccess

Copyright ELSEVIER SCIENCE SA

Palavras-Chave #Oxide materials #Mechanochemical processing #Microstructure #Magnetic measurements #X-ray diffraction #CATION DISTRIBUTION #NANOPARTICLES #FERRITES #MAGNETIZATION #TRANSITION #FE3O4 #Chemistry, Physical #Materials Science, Multidisciplinary #Metallurgy & Metallurgical Engineering
Tipo

article

original article

publishedVersion