Publikace na Matematicko-fyzikální fakulta |
2014
Abstrakt
In this work we apply nuclear magnetic resonance (NMR) spectroscopy of Fe-57 nuclei for investigation of submicron and nanocrystalline iron oxide systems. The studied iron oxide particles are obtained from ferrous hydroxide gels (prepared from FeCl2 and KOH) by aging at elevated temperatures (90 degrees C) with KNO3 as oxidant.
The Fe-57 NAIR spectra of the samples are measured in temperature range 4.2-370 K in a zero external magnetic field. Signals of Fe-57 nuclei assigned to tetrahedral and octahedral iron sites are well resolved.
The NMR spectra and their temperature dependences are compared with those of stoichiometric and nonstoichiometric magnetite single crystals, as well as with samples of maghemite.