Τίτλος:
Temperature study of magnetic resonance spectra of co-modified (Co,N)-TiO2 nanocomposites
Γλώσσες Τεκμηρίου:
Αγγλικά
Περίληψη:
The (nCo,N)-TiO2 (n = 1, 5 and 10 wt.% of Co) nanocomposites were investigated by magnetic resonance spectroscopy in 4 K to 290 K range. Analyses of ferromagnetic/electron paramagnetic resonance (FMR/EPR) spectra in terms of four Callen lineshape components revealed the existence of two types of magnetic centers, one derived from metallic cobalt nanoparticles in superparamagnetic (SPM) phase and the other from cobalt clusters in the TiO2 lattice. Additionally, at low temperature the EPR spectrum arising from Ti3+ ions was also registered. Both relaxations of the Landau-Lifshitz type and the Bloch-Bloembergen type played an important role at high temperature in determining the linewidths and the latter relaxation was prevailing at low temperature. Analysis of the integrated intensity showed that the SPM signal is due to small size FM cobalt nanoparticles while the paramagnetic signal from Co clusters originates from those nanoparticles in which the concentration of magnetic polarons is below the percolation threshold. © 2016 Wroclaw University of Technology.
Συγγραφείς:
Guskos, N.
Typek, J.
Zolnierkiewicz, G.
Guskos, A.
Berczynski, P.
Dolat, D.
Mozia, S.
Aidinis, K.
Kruk, K.
Morawski, A.W.
Περιοδικό:
Materials Science-Poland
Εκδότης:
Walter de Gruyter GmbH
Λέξεις-κλειδιά:
Cobalt; Cobalt compounds; Magnetic resonance; Magnetic resonance spectroscopy; Magnetism; Nanocomposites; Nanomagnetics; Nanoparticles; Paramagnetic resonance; Paramagnetism; Photocatalysts; Polarons; Resonance; Solvents; Temperature; Titanium dioxide, Cobalt nanoparticles; Integrated intensities; Magnetic resonance spectra; Nano-titanium dioxide; Paramagnetic signals; Percolation thresholds; Superparamagnetics; Temperature study, Electron spin resonance spectroscopy
DOI:
10.1515/msp-2016-0042
