2005/05/31 by E. Lima Jr., Enio Lima, A.L. Brandl +5
Energy · Materials Science · Physics and Astronomy · #Anisotropy #Condensed matter physics #Ferromagnetism #Iron oxide chemistry and applications #Magnetic Properties and Synthesis of Ferrites #Magnetic anisotropy #Magnetic field #Magnetic moment #Magnetic nanoparticles #Magnetic properties of thin films #Magnetite #Magnetization #Materials science #Nanoparticle #Nanotechnology #Physics #Spin canting #cond-mat.mtrl-sci
paper · pdf · doi:10.1063/1.2191471
published as Journal of Applied Physics, 99 (2006) 083908 · 11 pages, 7 figures, 3 Tables
openalex publication_date 2006/04/15 · arxiv created 2006/05/26 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We have studied the magnetic behavior of dextran-coated magnetite (Fe3O4) nanoparticles with median particle size ⟨d⟩=8nm. Magnetization curves and in-field Mössbauer spectroscopy measurements showed that the magnetic moment MS of the particles was much smaller than the bulk material. However, we found no evidence of magnetic irreversibility or nonsaturating behavior at high fields, usually associated to spin canting. The values of magnetic anisotropy Keff from different techniques indicate that surface or shape contributions are negligible. It is proposed that these particles have bulklike ferromagnetic structure with ordered A and B sublattices, but nearly compensated the magnetic moments. The dependence of the blocking temperature with frequency and applied fields, TB(H,ω), suggests that the observed nonmonotonic behavior is governed by the strength of interparticle interactions.