Dimerization and low-dimensional magnetism in nanocrystalline TiO2 semiconductors doped by Fe and Co

Autor: A. F. Gubkin, Danil W. Boukhvalov, V. R. Galakhov, Anatoly Ye. Yermakov, A.V. Korolyov, L. S. Molochnikov, E.V. Rosenfeld, Artem S. Minin, V. V. Mesilov, M. A. Uimin, A.S. Volegov
Jazyk: angličtina
Rok vydání: 2019
Předmět:
IONS
History
DIMERIZATION
Materials science
Magnetism
LOW CONCENTRATIONS
QUANTUM MECHANICAL MODEL
TITANIUM DIOXIDE
MAGNETIC CHARACTERIZATION
PARAMAGNETIC CONTRIBUTION
METAL NANOPARTICLES
Education
law.invention
Paramagnetism
Condensed Matter::Materials Science
EXCHANGE INTERACTIONS
OXIDE SEMICONDUCTORS
law
LOW-DIMENSIONAL MAGNETISM
Physics::Atomic and Molecular Clusters
DENSITY FUNCTIONAL THEORY
Electron paramagnetic resonance
High-resolution transmission electron microscopy
NANOCRYSTALLINE TIO2
X-ray absorption spectroscopy
Dopant
IRON
SQUID MAGNETOMETRY
PARAMAGNETIC RESONANCE
Magnetic semiconductor
HIGH RESOLUTION TRANSMISSION ELECTRON MICROSCOPY
PARAMAGNETISM
Computer Science Applications
ELECTRON SPIN RESONANCE SPECTROSCOPY
NANOCRYSTALS
TIO2 NANOPARTICLES
MAGNETOMETRY
X RAY ABSORPTION SPECTROSCOPY
X RAY DIFFRACTION ANALYSIS
Physical chemistry
Density functional theory
Condensed Matter::Strongly Correlated Electrons
MAGNETIC SEMICONDUCTORS
ELECTRON PARAMAGNETIC RESONANCE SPECTROSCOPY
Zdroj: Journal of Physics: Conference Series
Popis: 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 Fe3+ and Co2+ ions in the high-spin state and negative exchange interactions between them. The important conclusions is that the distribution of dopants in the TiO2 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 TiO2:(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.
Databáze: OpenAIRE
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