Wyniki wyszukiwania - BazTech

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FMR study of samples obtained by nitriding and nitrides reduction of nanocrystalline iron

Typek J., Guskos N., Zolnierkiewicz G., Guskos A., Kielbasa K., Pelka R., Arabczyk W.

Materials Science Poland

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2016

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Vol. 34, No. 1

6--12

EN

Samples obtained by nitriding of promoted nanocrystalline iron and the nitrides reduction at various nitriding potential in terms of thermodynamic parameters were investigated by electron paramagnetic resonance/ferromagnetic resonance (EPR/FMR) method at room temperature. Experimental FMR spectra were fitted by the Dysonian-type resonance lines arising from the presence of different Fe–N phases. The obtained FMR parameters allowed us to identify the component phases and to determine their magnetic properties. In general, the proposed simple method of decomposition of the FMR spectra produced results on the phase content in investigated samples that were consistent with XRD measurements and additionally, magnetic characteristics of the studied nanomagnets.

2

Dyson line and modified Dyson line in the EPR measurements

Popovych V., Bester M., Stefaniuk I., Kuzma M.

Nukleonika

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2015

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Vol. 60, No. 3, part 1

385--388

EN

The difficulty in determining the electron paramagnetic resonance (EPR) line parameters of ferromagnetic semiconductors has been addressed. For these materials, the resonance line is very broad and lies at low resonance fi eld, so that only a part of the line can be detected experimentally. Moreover, the line is of asymmetric (Dysonian) shape as described by the line shape parameter α. We have compared values of line parameters derived by computer fi tting of the whole experimental EPR line to the Dyson function (or modified Dyson function) with the values obtained by applying this procedure to the left and the right half of the line.

3

The influence of substrate and cap layer on magnetic characteristics of some multilayers

Staniucha I., Urbaniak-Kucharczyk A.

Materials Science Poland

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2007

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Vol. 25, No. 2

371--375

EN

The influence of non-symmetrical boundary conditions, caused by different materials of the substrate and covering, on some properties of the systems consisting of magnetic layers separated by nonmagnetic spacer have been considered. Magnetic properties like spin wave patterns, FMR spectra, Curie temperature, magnetization and spin wave parameter B have been investigated for symmetrical and nonsymmetrical structures like: Cu(111)/(Fe/Cu)n/Fe/Cu/Si(111), vacuum/(Fe/Cu(111))n/Fe/vacuum, vacuum/( Fe/Cu)n/Si(111) and Cu/(Fe/Cu)n/Fe/GaAs, vacuum/(Fe/Cu)n/Fe/GaAs, where n is equal 1 or 2. Influence of roughness on selected characteristics of magnetic systems with non-symmetrical conditions on external surfaces has been also investigated.

4

FMR study of nanocarbon materials obtained by carburisation of nanocrystalline iron

Narkiewicz U., Arabczyk W., Pełech I., Guskos N., Typek J., Maryniak M., Woźniak M. J., Matysiak H., Kurzydłowski K. J.

Materials Science Poland

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2006

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Vol. 24, No. 4

1067--1075

EN

Samples of nanocrystalline iron were carburised with ethylene and next reduced with hydrogen. Both carburisation and reduction were monitored by the thermogravimetry. The obtained samples were characterised using X-ray diffraction, high-resolution transmission electron microscopy and ferromagnetic resonance. The samples after carburisation contained cementite (Fe3C) and carbon deposit (nanofibres and nanotubes). As the result of reduction with hydrogen at 450 or 500 °C cementite was reduced to iron. A major part of carbon was also hydrogenated, only thin carbon nanotubes remained. The FMR spectra of the prepared samples were recorded at room temperature. The sample after carburisation has shown a wide FMR line with weak intensity while the resonance field has been shifted to lower magnetic field. This spectrum has been attributed to the presence of cementite. The FMR lines corresponding to samples after reduction are more intense and are connected with the presence of alfa-Fe nanoparticle conglomerates.