J. Dolinek 1 Anisotropic Physical Properties of Decagonal Quasicrystals Janez Dolinek Joef Stefan Institute, University of Ljubljana, Slovenia J. Dolinek 2 Slovenia area: km 2 population: 2 million Ljubljana Julian AlpsLake Bled Adriatic seaLipizaner horses J. Dolinek 3 Joef Stefan Institute, Ljubljana, Slovenia staff: 850 revenues (2012): 52 MEur physicschemistry biology J. Dolinek 4 Structure of decagonal quasicrystals Geometrical description: periodic stacking of quasiperiodic atomic layers periodic 10-fold directionquasiperiodic atomic layers P J. Dolinek 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. Dolinek 6 Physical properties investigated: - electrical resistivity (T) - magnetism (T), M(H) - thermoelectric powerS(T) - Hall coefficientR H (T) - thermal conductivity(T) J. Dolinek 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. Dolinek 8 d-Al-Co-Ni: samples preparation P. Gille, G. Meisterernst, N. Faber, J. Crystal Growth 275, 224 (2005) P P J. Dolinek 9 Symmetry analysis P General form of a tensorial physical property (2 nd rank tensor) for a decagonal point group: J. Dolinek 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. Dolinek 11 d-Al 70 Co 10 Ni 20 : orientation-dependent 27 Al NMR spectra J. Dolinek 12 d-Al 70 Co 10 Ni 20 : orientation-dependent 27 Al NMR satellite intensity J. Dolinek 13 d-Al 70 Co 10 Ni 20 : orientation-dependent 27 Al NMR satellite intensity J. Dolinek 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 Laissardire et al., Phys. Rev. Lett. 97, (2006) J. Dolinek 15 d-Al 70 Co 10 Ni 20 :Hall coefficient P M. Bobnar et al., Phys. Rev. B 85, (2012) J. Dolinek 16 : d-Al 70 Co 10 Ni 20 : thermal conductivity P M. Bobnar et al., Phys. Rev. B 85, (2012) J. Dolinek 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. Dolinek 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. Dolinek 19 Coworkers and cooperation J. Stefan Institute, Ljubljana Stane Vrtnik Matej Bobnar Zvonko Jaglii Ludwig-Maximilian University, Munich Peter Gille Institute of Physics, Zagreb Ana Smontara