Back to Search
Start Over
High-temperature magnetic properties of noninteracting single-domain Fe3O4 nanoparticles
- Publication Year :
- 2010
-
Abstract
- Magnetic measurements have been performed on 40-nm sphere-like Fe3O4 nanoparticles using a Quantum Design vibrating sample magnetometer. Coating Fe3O4 nanoparticles with SiO2 effectively eliminates magnetic interparticle interactions so that the coercive field HC in the hightemperature range between 300 K and the Curie temperature (855 K) can be well fitted by an expression for noninteracting randomly oriented single-domain particles. From the fitting parameters, the effective anisotropy constant K is found to be (1.68 \pm 0.17) \times 105 erg/cm3, which is slightly larger than the bulk magnetocrystalline anisotropy constant of 1.35 \times 105 erg/cm3. Moreover, the inferred mean particle diameter from the fitting parameters is in quantitative agreement with that determined from transmission electron microscope. Such a quantitative agreement between data and theory suggests that the assemble of our SiO2-coated sphere-like Fe3O4 nanopartles represents a good system of noninteracting randomly-oriented single-domain particles.<br />Comment: 9 pages, 5 figures
Details
- Database :
- arXiv
- Publication Type :
- Report
- Accession number :
- edsarx.1010.5264
- Document Type :
- Working Paper
- Full Text :
- https://doi.org/10.1016/j.physleta.2011.02.040