Size effects in the conduction electron spin resonance of anthracite and higher anthraxolite
| Autor: | Roman Strzelczyk, Krzysztof Tadyszak, Emerson Coy, Mariusz Maćkowiak, M.A. Augustyniak-Jabłokow |
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| Rok vydání: | 2015 |
| Předmět: |
Physics
Condensed matter physics Resonance 02 engineering and technology General Chemistry Electron 010402 general chemistry 021001 nanoscience & nanotechnology Thermal conduction 01 natural sciences Spectral line 0104 chemical sciences law.invention Amorphous solid Paramagnetism Nuclear magnetic resonance law Electrical resistivity and conductivity General Materials Science 0210 nano-technology Electron paramagnetic resonance |
| Zdroj: | Magnetic Resonance in Chemistry. 54:239-245 |
| ISSN: | 0749-1581 |
| Popis: | Electron paramagnetic resonance spectroscopy of conduction electrons, i.e. Conduction Electron Spin Resonance (CESR), is a powerful tool for studies of carbon samples. Conductive samples cause additional effects in CESR spectra that influence the shape and intensity of the signals. In cases where conduction electrons play a dominant role, whilst the influence of localized paramagnetic centres is small or negligible, the effects because of the spins on conduction electrons will dominate the spectra. It has been shown that for some ratios of the bulk sample sizes (d) to the skin depth (δ), which depend on the electrical conductivity, additional size effects become visible in the line asymmetry parameter A/|B|, which is the ratio of the maximum to the absolute, minimum value of the resonance signal. To study these effects the electrical direct current-conductivity and CESR measurements are carried out for two amorphous bulk coal samples of anthracite and a higher anthraxolite. The observed effects are described and discussed in terms of the Dyson theory. Copyright © 2015 John Wiley & Sons, Ltd. |
| Databáze: | OpenAIRE |
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