LATTICE EXCITATIONS IN ICOSAHEDRAL AL-MN-PD AND AL-RE-PD

We report results of measurements of the specific heat C-p(T) of a lar ge Czochralski-grown single grain of icosahedral Al68.2Mn9Pd22.8 and o f a high-quality single-phase sample of icosahedral Al70Re8.6Pd21.4 in the temperature range between 1.6 and 280 K. For icosahedral Al68.2Mn 9Pd22.8, the cubic-in-T term to the low-temperature specific heat C-p( T) is distinctly larger than the expected acoustic-phonon contribution calculated from the results of low-temperature measurements of the so und velocities nu(l) and nu(t), thus indicating a large excess specifi c heat C-ex(T). The same conclusion can be reached for Al70Re8.6Pd21.4 . [S0163-1829(98)02517-X]..