Open AccessDimerization and low-dimensional magnetism in nanocrystalline TiO2 semiconductors doped by Fe and Co
Author(s) -
A. Ye. Yermakov,
Danil W. Boukhvalov,
М. А. Уймин,
V. V. Mesilov,
Artem S. Minin,
V. R. Galakhov,
A.V. Korolyov,
А. С. Волегов,
E. V. Rosenfeld,
А. Ф. Губкин,
Л. С. Молочников
Publication year - 2019
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/1389/1/012026
Subject(s) - nanocrystalline material , electron paramagnetic resonance , paramagnetism , magnetic semiconductor , dopant , materials science , magnetism , doping , condensed matter physics , x ray absorption spectroscopy , spectroscopy , magnetometer , ion , analytical chemistry (journal) , squid , absorption spectroscopy , nuclear magnetic resonance , chemistry , nanotechnology , magnetic field , physics , quantum mechanics , chromatography , ecology , optoelectronics , organic chemistry , biology
The report is devoted to an analysis of the structural and magnetic state of the nanocrystalline diluted magnetic semiconductors based on TiO2 doped with Fe and Co atoms. Structural and magnetic characterization of samples was carried out using X-ray diffraction (XRD) analysis, transmission electron microscopy (TEM), X-ray absorption spectroscopy (XAS), electron paramagnetic resonance (EPR) spectroscopy, SQUID magnetometry, and the density functional theory (DFT) calculations. Analysis of the experimental data suggests the presence of non-interacting paramagnetic Fe 3+ and Co 2+ ions in the high-spin state and negative exchange interactions between them. The important conclusions is that the distribution of dopants in the TiO 2 matrix, even at low concentrations of 3d-metal dopant (less than one percent), is not random, but the 3d ions localization and dimerization is observed both on the surface and in the nanoparticles core. Thus, in the paper the quantum mechanical model for describing the magnetic properties of TiO 2 :(Fe, Co) was suggested. The model operates only with two parameters: paramagnetic contribution of non-interacting 3d-ions and dimers having different exchange interactions between 3d magnetic carriers.