Magnetic properties of nanocrystalline CoFe2O4 dispersed in amorphous silica

Francesco Congiu; Giorgio Concas; Guido Ennas; Andrea Falqui; Dino Fiorani; Giaime Marongiu; Sergio Marras; Giorgio Spano; Alberto M. Testa

doi:10.1016/j.jmmm.2003.12.267

Magnetic properties of nanocrystalline CoFe₂O₄ dispersed in amorphous silica

Francesco Congiu, Giorgio Concas, Guido Ennas, Andrea Falqui^*, Dino Fiorani, Giaime Marongiu, Sergio Marras, Giorgio Spano, Alberto M. Testa

^*Corresponding author for this work

Research output: Contribution to journal › Conference article › peer-review

24 Scopus citations

Abstract

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 900°C. Mössbauer spectra show the presence of CoFe₂O₄ nanoparticles in the superparamagnetic state at 293K and mainly in the blocked state at 77K. This is confirmed by ZFC/FC measurements giving evidence of a distribution of blocking temperatures, centered at 50K.

Original language	English (US)
Pages (from-to)	1561-1562
Number of pages	2
Journal	Journal of Magnetism and Magnetic Materials
Volume	272-276
DOIs	https://doi.org/10.1016/j.jmmm.2003.12.267
State	Published - May 2004
Externally published	Yes
Event	Proceedings of the International Conference on Magnetism - Rome, Italy Duration: Jul 27 2003 → Aug 1 2003

Keywords

Cobalt ferrite
Nanocomposite
Superparamagnetism

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials
Condensed Matter Physics

Access to Document

10.1016/j.jmmm.2003.12.267

Cite this

@article{9e5a53348fef4f4c9385b2e03c2964f2,

title = "Magnetic properties of nanocrystalline CoFe2O4 dispersed in amorphous silica",

abstract = "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 900°C. M{\"o}ssbauer spectra show the presence of CoFe2O4 nanoparticles in the superparamagnetic state at 293K and mainly in the blocked state at 77K. This is confirmed by ZFC/FC measurements giving evidence of a distribution of blocking temperatures, centered at 50K.",

keywords = "Cobalt ferrite, Nanocomposite, Superparamagnetism",

author = "Francesco Congiu and Giorgio Concas and Guido Ennas and Andrea Falqui and Dino Fiorani and Giaime Marongiu and Sergio Marras and Giorgio Spano and Testa, {Alberto M.}",

year = "2004",

month = may,

doi = "10.1016/j.jmmm.2003.12.267",

language = "English (US)",

volume = "272-276",

pages = "1561--1562",

journal = "Journal of Magnetism and Magnetic Materials",

issn = "0304-8853",

publisher = "Elsevier",

note = "Proceedings of the International Conference on Magnetism ; Conference date: 27-07-2003 Through 01-08-2003",

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TY - JOUR

T1 - Magnetic properties of nanocrystalline CoFe2O4 dispersed in amorphous silica

AU - Congiu, Francesco

AU - Concas, Giorgio

AU - Ennas, Guido

AU - Falqui, Andrea

AU - Fiorani, Dino

AU - Marongiu, Giaime

AU - Marras, Sergio

AU - Spano, Giorgio

AU - Testa, Alberto M.

PY - 2004/5

Y1 - 2004/5

N2 - 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 900°C. Mössbauer spectra show the presence of CoFe2O4 nanoparticles in the superparamagnetic state at 293K and mainly in the blocked state at 77K. This is confirmed by ZFC/FC measurements giving evidence of a distribution of blocking temperatures, centered at 50K.

AB - 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 900°C. Mössbauer spectra show the presence of CoFe2O4 nanoparticles in the superparamagnetic state at 293K and mainly in the blocked state at 77K. This is confirmed by ZFC/FC measurements giving evidence of a distribution of blocking temperatures, centered at 50K.

KW - Cobalt ferrite

KW - Nanocomposite

KW - Superparamagnetism

UR - http://www.scopus.com/inward/record.url?scp=2642576807&partnerID=8YFLogxK

U2 - 10.1016/j.jmmm.2003.12.267

DO - 10.1016/j.jmmm.2003.12.267

M3 - Conference article

AN - SCOPUS:2642576807

SN - 0304-8853

VL - 272-276

SP - 1561

EP - 1562

JO - Journal of Magnetism and Magnetic Materials

JF - Journal of Magnetism and Magnetic Materials

T2 - Proceedings of the International Conference on Magnetism

Y2 - 27 July 2003 through 1 August 2003

ER -