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1

Multidimensional NQR Spectroscopy - A New Tool in Studies of Molecular Dynamics

100%

Maćkowiak M.

Acta Physica Polonica A

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2005

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vol. 108

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issue 1

61-72

EN

Two-dimensional exchange ^{35}Cl nuclear quadrupole resonance spectroscopy for studies of the CCl_3-group reorientation processes in hexachloroethane and chloral hydrate has been applied. Experimental results were interpreted on the basis of the 2D exchange nuclear quadrupole resonance theory, which takes into account the off-resonance irradiation. It has been demonstrated that 2D nuclear quadrupole resonance exchange spectroscopy is appropriate for quantitative studies of exchange processes in molecular crystals containing quadrupolar nuclei. The method is of particular value for the detection of exchange networks in systems with many sites. Thus, detailed information on the exchange pathways within a network of structural isomers can be deduced and a proper assignment of the nuclear quadrupole resonance lines can be made. Temperature dependence of the exchange rate was studied. The mixing dynamics by exchange and the expected cross-peak intensities have been derived.

2

FMR Evidence of Stable Ferromagnetic Correlations at Zigzag Edge States in Graphene

51%

Augustyniak-Jabłokow M., Maćkowiak M., Tadyszak K., Strzelczyk R.

Acta Physica Polonica A

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2015

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vol. 127

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issue 2

537-539

EN

We studied magnetic properties of a composite of paraffin and graphene flakes. Magnetic properties of this composite were investigated by ferromagnetic resonance/electron spin resonance technique. The ferromagnetic resonance signal from graphene suspension in paraffin is broad and shifted from magnetic field corresponding to g ≈ 2 to the low magnetic field. The temperature dependence of the spectra shows that magnetic ordering in the studied system is sensitive to thermal fluctuations. These features are expected for the 1D ferromagnetism and the obtained results are analyzed in the frame of the theoretical predictions concerning magnetic correlations at graphene edges. Therefore, based on our investigation we can conclude the existence of the magnetic edges in graphene and presence of the ferromagnetic correlations between edge spins.

3

Magnetic Centres in Functionalized Graphene

51%

Majchrzycki Ł., Augustyniak-Jabłokow M., Strzelczyk R., Maćkowiak M.

Acta Physica Polonica A

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2015

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vol. 127

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issue 2

540-542

EN

Discussion of the origin of paramagnetic centres observed by electron paramagnetic resonance in graphene oxide (GO) and reduced graphene oxide (rGO) is done on the assumption that GO can be considered as a functionalized graphene. This leads to the conclusion that the narrow signal with g close to 2, observed for GO and thermally reduced GO, is due to paramagnetic centres localized on defects and exchange coupled to conduction electrons. Randomness of graphene modification results in variety of parameters of EPR signals. The broad signals observed in GO and rGO and ascribed to magnetic clusters on the zig-zag edge states indicate that the edge magnetism can be preserved by functionalization.

4

The Knapsack-Lightening problem and its application to scheduling HRT tasks

45%

Nawrocki J. R., Błażewicz J., Complak W., Kopczyńska S., Maćkowiak M.

Bulletin of the Polish Academy of Sciences: Technical Sciences

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2009

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vol. 57

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issue 1

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3 Acta Physica Polonica A

1 Bulletin of the Polish Academy of Sciences: Technical Sciences

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4 Maćkowiak M.

2 Augustyniak-Jabłokow M.

2 Strzelczyk R.

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1 Complak W.

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1 Majchrzycki Ł.

1 Nawrocki J. R.

1 Tadyszak K.

Multidimensional NQR Spectroscopy - A New Tool in Studies of Molecular Dynamics

FMR Evidence of Stable Ferromagnetic Correlations at Zigzag Edge States in Graphene

Magnetic Centres in Functionalized Graphene

The Knapsack-Lightening problem and its application to scheduling HRT tasks