Specific heat of an icosahedral superconductor, Mg sub 3 Zn sub 3 Al sub 2.

Specific heat measurements are reported for cubic (c), icosahedral (i), and amorphous (a) phases of Mg sub 3 Zn sub 3 Al sub 2 in the temperature range 0.04-5K. All three phases are superconducting, with T =0.3, 0.41, and 0.75K, respectively. The electronic density of states N(0) is comparable to that expected on the free electron model for all three phases. Compared to the c-phase, significant lattice softening is observed in the i-phase and, especially, in the a-phase indicating an increase in the electron- phonon coupling parameter lambda with decreasing symmetry.