RT journal article
T1 Ferromagnetic resonance of nanocomposites based on iron oxides
A1 Ortega Ponce, Daniel
A1 Barrera-Solano, M. Carmen
A1 Garitaonandía, J.S.
A1 Domínguez de la Vega, Manuel
A2 Física de la Materia Condensada
K1 ferromagnetic resonance
K1 nanocomposites
K1 sol-gel
K1 iron oxides
AB The present work has been focused on the interpretation of variable temperature ferromagnetic resonance spectra of mixed α-Fe2O3 and γ-Fe2O3–SiO2 nanocomposites, combined with previous magnetization and electron microscopy results. These materials have been shown to exhibit very promising applications as magneto-optical sensors. Sol–gel processing has been employed to synthesize in situ iron oxide nanoparticles within a transparent SiO2 matrix. Monolithic samples have been obtained employing formamide as drying control chemical agent, following a specific processing route aimed to generate γ-Fe2O3 nanoparticles. Although γ-Fe2O3 is the main phase, the formation of some amount of α-Fe2O3 phase is unavoidable. Variable temperature ferromagnetic resonance spectra are composed of: (i) a high field peak attributed to γ-Fe2O3 nanoparticles. This peak comes from the overlapping of the two expected peaks for ellipsoidal particles. When temperature is decreased, this peak broadens as a consequence of size and shape distributions; (ii) at medium fields (ca. 1525 Oe) and low temperatures, the ferrimagnetic peak from uncompensated magnetic moments in γ-Fe2O3 shows up; and finally, (iii) at low fields and temperatures, the anti-resonance peak due to normal antiferromagnetic α-Fe2O3 phase is also visible.
SN 1546-198X
YR 2007
FD 2007-03-01
LK http://hdl.handle.net/10498/35249
UL http://hdl.handle.net/10498/35249
LA eng
DS Repositorio Institucional de la Universidad de Cádiz
RD 21-sep-2026