RT journal article
T1 Size and surface effects in the magnetic properties of maghemite and magnetite coated nanoparticles
A1 Ortega Ponce, Daniel
A1 Velez-Fort, Emilio
A1 García, D. A.
A1 García, Ramón
A1 Litrán Ramos, Rocío
A1 Barrera-Solano, M. Carmen
A1 Ramírez del Solar, Milagrosa
A1 Domínguez de la Vega, Manuel
A2 Física de la Materia Condensada
K1 maghemite
K1 magnetite
K1 Bloch's law
K1 superparamagnetism
AB An increasing number of promising applications for future technology is arising from size constraints in nanoparticles (NPs) and from the chemical manipulation of their surfaces. In this work, we analyse the finite-size and surface effects on polyacrylic acid-coated Fe3O4 NPs and oleic acid-coated γ-Fe2O3 NPs by studying their magnetization curves at different temperatures. The measured thermal dependence of the saturation magnetization is no longer explained by the typical T3/2 Bloch law, yielding higher values than those expected for its exponent. When incorporated in polymeric matrixes to form magnetic transparent nanocomposites, the oleic acid-coated γ-Fe2O3 NPs also deviate from Bloch’s law, but following the opposite trend observed in free coated NPs.
SN 1364-503X
YR 2010
FD 2010-09-28
LK http://hdl.handle.net/10498/35266
UL http://hdl.handle.net/10498/35266
LA eng
DS Repositorio Institucional de la Universidad de Cádiz
RD 21-sep-2026