J. Dolinšek 1 Anisotropic Physical Properties of Decagonal Quasicrystals Janez Dolinšek Jožef Stefan Institute, University of Ljubljana, Slovenia

J. Dolinšek 2 Slovenia area: km 2 population: 2 million Ljubljana Julian AlpsLake Bled Adriatic seaLipizaner horses

J. Dolinšek 3 “Jožef Stefan” Institute, Ljubljana, Slovenia staff: 850 revenues (2012): 52 MEur physicschemistry biology

J. Dolinšek 4 Structure of decagonal quasicrystals Geometrical description: periodic stacking of quasiperiodic atomic layers periodic 10-fold directionquasiperiodic atomic layers P

J. Dolinšek 5 Investigated phase Decagonal quasicrystal d-Al-Co-Ni: - symmetry: decagonal - chemical composition (at. %): Al 70 Co 10 Ni 20 2 atomic layers within one periodic unit of 0.4 nm along 10 5 axis

J. Dolinšek 6 Physical properties investigated: - electrical resistivity ρ (T) - magnetism χ (T), M(H) - thermoelectric powerS(T) - Hall coefficientR H (T) - thermal conductivityκ(T)

J. Dolinšek 7 Anisotropic physical properties of d-Al-Co-Ni measurements performed along four crystallographic directions (three “in-plane” and the stacking “10-fold” direction)... stacking directionP P

J. Dolinšek 8 d-Al-Co-Ni: samples preparation P. Gille, G. Meisterernst, N. Faber, J. Crystal Growth 275, 224 (2005) P P

J. Dolinšek 9 Symmetry analysis P General form of a tensorial physical property (2 nd rank tensor) for a decagonal point group:

J. Dolinšek 10 d-Al 70 Co 10 Ni 20 : symmetry analysis by 27 Al NMR 27 Al NMR spectrum central line satellites M. Bobnar et al., Phys. Rev. B 85, (2012)

J. Dolinšek 11 d-Al 70 Co 10 Ni 20 : orientation-dependent 27 Al NMR spectra

J. Dolinšek 12 d-Al 70 Co 10 Ni 20 : orientation-dependent 27 Al NMR satellite intensity

J. Dolinšek 13 d-Al 70 Co 10 Ni 20 : orientation-dependent 27 Al NMR satellite intensity

J. Dolinšek 14 d-Al 70 Co 10 Ni 20 : electrical resistivity P P T-dependent resistivity in the Q plane Theory: Model of slow charge carriers G. Trambly de Laissardière et al., Phys. Rev. Lett. 97, (2006)

J. Dolinšek 15 d-Al 70 Co 10 Ni 20 :Hall coefficient P M. Bobnar et al., Phys. Rev. B 85, (2012)

J. Dolinšek 16 : d-Al 70 Co 10 Ni 20 : thermal conductivity P M. Bobnar et al., Phys. Rev. B 85, (2012)

J. Dolinšek 17 Magnetization vs. magnetic field and magnetic susceptibility P P Stronger diamagnetism for the field along 10-fold axis: atomic rings in the Q plane form diamagnetic circular current loops W. Steurer et al., Acta Cryst. B 49, 661 (1993)

J. Dolinšek 18 Conclusions - electrical, thermal and magnetic properties of d-Al-Co-Ni decagonal quasicrystal are highly anisotropic; - stacking direction is the most conducting direction for the electricity and heat; - origin of anisotropy is the anisotropic stacked-layer atomic structure.

J. Dolinšek 19 Coworkers and cooperation J. Stefan Institute, Ljubljana Stane Vrtnik Matej Bobnar Zvonko Jagličić Ludwig-Maximilian University, Munich Peter Gille Institute of Physics, Zagreb Ana Smontara