Magnetic Investigation of CoFe2O4 Nanoparticles Supported in Biocompatible Polymeric Microsphere

被引：14

作者：

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

Vaccari, C. B. ^{[2
]}

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

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

机构：

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

[2] Univ Sao Paulo, Fac Filosofia Ciencias & Letras Ribeirao Preto, Dept Quim, BR-14040901 Ribeirao Preto, SP, Brazil

来源：

IEEE TRANSACTIONS ON MAGNETICS | 2009年 / 45卷 / 10期

关键词：

Magnetic coercive field; magnetization isotherm; polymer dispersed CoFe2O4 nanoparticles; thermal blocking process; magnetic fluid; SUSCEPTIBILITY; PARTICLES; RESONANCE;

D O I：

10.1109/TMAG.2009.2026291

中图分类号：

TM [电工技术]; TN [电子技术、通信技术];

学科分类号：

0808 ; 0809 ;

摘要：

Magnetic investigation of spinel ferrite nanoparticles dispersed in biocompatible polymeric microspheres is reported in this study. X-ray diffraction data analysis confirms the presence of nanosized CoFe2O4 particles (mean size of similar to 8 nm). This finding is corroborated by transmission electron microscopy micrographs. Magnetization isotherms suggest a spin disorder likely occurring at the nanoparticle's surface. The saturation magnetization value is used to estimate particle concentration of 1.6 x 10(18) cm(-3) dispersed in the polymeric template. A T-1/2 dependence of the coercive field is determined in the low-temperature region (T < 30 K). The model of non-interacting mono-domains is used to estimate an effective magnetic anisotropy of K-eff = 0.6 x 10(5) J/m(3). The K-eff value we found is lower than the value reported for spherically-shaped CoFe2O4 nanoparticles, though consistent with the low coercive field observed in the investigated sample.

引用

页码：4059 / 4062

页数：4

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