Magnetic properties of nanocrystalline CoFe2O4 dispersed in amorphous silica

被引：19

作者：

Congiu, F

Concas, G

Ennas, G

Falqui, A

Fiorani, D

Marongiu, G

Marras, S

Spano, G

Testa, AM

机构：

[1] Univ Cagliari, Dipartimento Sci Chim, I-09042 Monserrato, CA, Italy

[2] INFM, I-09042 Monserrato, CA, Italy

[3] CNR, ISM, Area Ric, I-00016 Monterotondo, Italy

来源：

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS | 2004年 / 272卷

关键词：

nanocomposite; cobalt ferrite; superparamagnetism;

D O I：

10.1016/j.jmmm.2003.12.267

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

Almost spherical CoFe2O4 nanocrystals with a narrow size distribution centered around 2.5(5)nm, uniformly dispersed in an amorphous SiO2 matrix have been prepared by high energy ball milling followed by thermal treatment at 900degreesC. Mossbauer spectra show the presence of CoFe2O4 nanoparticles in the superparamagnetic state at 293 K and mainly in the blocked state at 77 K. This is confirmed by ZFC/FC measurements giving evidence of a distribution of blocking temperatures, centered at 50 K. (C) 2003 Published by Elsevier B.V.

引用

页码：1561 / 1562

页数：2

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[4]

SLONCZEWSKI JC, 1959, J APPL PHYS, V32, pS253

[5]

Tronc E, 1996, NUOVO CIMENTO D, V18, P163, DOI 10.1007/BF02458890

[6] Surface-related properties of γ-Fe2O3 nanoparticles [J].

Tronc, E ;

Ezzir, A ;

Cherkaoui, R ;

Chanéac, C ;

Noguès, M ;

Kachkachi, H ;

Fiorani, D ;

Testa, AM ;

Grenèche, JM ;

Jolivet, JP .

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 2000, 221 (1-2) :63-79

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