Projects / Programmes
Physics of quasicrystals – novel materials for energy storage
| Code |
Science |
Field |
Subfield |
| 1.02.00 |
Natural sciences and mathematics |
Physics |
|
| Code |
Science |
Field |
| P260 |
Natural sciences and mathematics |
Condensed matter: electronic structure, electrical, magnetic and optical properties, supraconductors, magnetic resonance, relaxation, spectroscopy |
quasicrystals, hydrogen storage, nuclear magnetic resonance, atomic diffusion, novel materials, metallic alloys, computer modelling
Researchers (2)
| no. |
Code |
Name and surname |
Research area |
Role |
Period |
No. of publicationsNo. of publications |
| 1. |
03939 |
PhD Janez Dolinšek |
Physics |
Head |
2005 - 2007 |
769 |
| 2. |
20209 |
PhD Martin Klanjšek |
Physics |
Researcher |
2005 - 2007 |
193 |
Organisations (1)
| no. |
Code |
Research organisation |
City |
Registration number |
No. of publicationsNo. of publications |
| 1. |
0106 |
Jožef Stefan Institute |
Ljubljana |
5051606000 |
90,706 |
Abstract
Within the proposed project we aim to address three contextual packages. As a good deal of interesting physical properties of quasicrystals originate in the specific behaviour of conduction electrons, one should have knowledge of these properties and their relationship to the specific structure of quasicrystals in order to understand physical properties of qusicrystals properly. In the final instance, this openes also the way to the potential use. It is thus reasonable to compare electronic properties of quasicrystals to the electronic properties of related metallic alloys. We aim to perform a detailed comparative study of a large number of metallic samples with different metallic characters. For the conclusions to be reliable, the structure, phase and chemical composition of the samples will be analysed. We expect to confirm the hypothesis that the electronic density of states at Fermi level increases with the pronounced metallic character.
The determination of the structure of quasicrystals is one of the central problems in this field of research. Up to now none of the known quasicrystals has been completely deciphered, however, the complete knowledge of structure would open the way into the understanding of interesting physical properties – and thus strenghten the possibilities for practical use. Our research group was the first to observe that the NMR spectrum of icosahedral quasicrystals exhibits weak orientation-dependence, on the basis of which it is in principle possible to infer the distribution of the electric field gradients and, in turn, make conclusions about the adequacy of the existing structural models. The sequence of this inference, however, is far from trivial. We intend to find a detailed connection between the measured orientation-dependence and the distribution of electric field gradients. In addition to the sample from the AlPdMn family, we aim to investigate the sample from the AlCuFe family as well, both being known to have different structures. We expect that the measured NMR spectrum orientation-dependence will turn out to be different in two cases. In this way we would arrive at the new method for the structural determination, the one that is complementary to the existing ones.
In some quasicrystals it is possible to load large amounts of hydrogen, this ability opening the way to the promising fuel-cells of the near future. The key factor that caharcterizes good hydrogen-storage materials is the ability to get hydrogen into and out of the material easily and within the reasonable time, this being related to the mobility of hydrogen atoms within the (quasi)crystalline lattice. Our research group was the first to use the method of the NMR diffusion in a static stray field of a superconducting magnet to directly determine the hydrogen difussion constant. The exact microscopic mechanism of hydrogen difussion, however, is not known as yet. We intend to investigate this mechanism in the quasicrystals from the ZrCuNiAl and Ti(Zr/Hf)Ni families by means of spin-lattice-relaxation-rate-dispersion measurements and measurements of the temperature-dependent deuteron NMR spectra. In the last case the samples will be loaded by heavy hydrogen.
