Melting entropy of Al-based quasicrystals

The melting enthalpies and temperatures of quasiperiodic and periodic phase s in Al-Cu-Co, Al-Ni-Co, Al-Ni-Fe and Al-Cu-Fe were measured by differentia l thermal analysis. From these data the melting entropies of the different phases were derived. The results are discussed in terms of the mutual stabi lity of the quasicrystalline and crystalline phases in these alloy systems, indicating that the entropy of mixing plays an important role for the stab ilization of quasicrystalline phases at ternary alloy compositions. (C) 199 9 Elsevier Science B.V. All rights reserved.