Eleventh International Conference on Internal Friction and Ultrasonic Attenuation in Solids
J. Phys. IV France 06 (1996) C8-239-C8-242
Phason Relaxation Mechanisms in Al-Pd-Mn Single-QuasicrystalsM. Weller1, M. Feuerbacher2, J. Diehl1 and K. Urban2
1 Max-Planck-Institut für Metallforschung, Institut für Werkstoffwissenschaft, Seestrasse 92, 70174 Stuttgart, Germany
2 Institut für Festkörperforschung, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
Quasicrystals represent a new state of condensed matter which exhibits long-range quasiperiodic translational order and orientational order with noncrystallographic symmetry. Mechanical spectroscopy was applied for the study of defect properties in stable icosahedral single-quasicrystalline Al-Pd-Mn samples. Two mechanical loss maxima appear at 360 K and 870 K for a measuring frequency of f≈3Hz. The relaxation parameters for both peaks were determined as H = 0.98 eV, τoo-1=4.5.1014s-1 for the low temperature peak, and H = 4.0 eV, τoo-1=3.0.1024s-1 for the high temperature peak, respectively. Both peaks are related to phason defects which are characteristic for the quasicrystalline structure.
© EDP Sciences 1996