engleski

Electronic transport in high quality d-AlCoNi quasiperiodic crystals

Since their discovery, [1] quasiperiodic crystals have intrigued scientists because of their unique crystal structure and physical properties resulting from it. For long time, their genuine transport properties were screened with various defects and irregularities present in their crystal structure. [2-5] Only recently we were able to address transport properties of high quality single crystals of decagonal d-AlCoNi quasiperiodic crystal. [6] Decagonal quasicrystals are ideal system for study of quasiperiodicity and its influence on transport properties. Their crystal structure possess periodicity (present in ordinary crystals) along one spatial direction and quasiperiodicity (distinctive for quasiperiodic crystals) in plane perpendicular to the periodic direction. We have measured electrical resistivity and thermopower of d-Al73Co13.5Ni13.5. Transport properties along periodic direction show almost ordinary metallic behavior. Electrical resistivity along quasiperiodic direction has PTC/NTC crossover above room temperature and thermopower is far from linear like metallic behavior. In both directions at low temperatures, there is shallow minimum in resistivity indicating effect of weak localization. Transport properties of d-AlCoNi are not very sensitive to crystal composition suggesting that we have measured true quasiperiodic properties. [1] D. Shechtman et al. Phys. Rev. Lett. , 53 (1984) 1951. [2] S. Martin et al. Phys. Rev. Lett., 67 (1991) 719. [3] J. T. Markert et al. J. Appl. Phys., 76 (1994) 6110. [4] D. G. Naugle et al. J. Non-Cryst. Solids 205-207 (1996) 17. [5] L. Shuyuan et al. Phys. Rev. Lett., 77 (1996) 1998. [6] M. Bobnar et al. Phys. Rev. B, 85 (2012) 024205.

d-AlCoNi. electronic transport

The paper was presented as a poster by Petar Popčević. This work was done within the activities of the European Integrated Center for the Development of New Metallic Alloys and Compounds - C-MAC.