Low temperature heat capacity and magnetic study of the quasicrystalline decagonal Al7 8Mn2 2 alloy

Abstract Low temperature heat capacity and magnetization measurements are reported for the quasicrystalline decagonal (T-phase) alloy Al 7 8 Mn 2 2 . The heat capacity measurements were performed over the temperature range from 0.5 to 5.0 K and for applied magnetic fields of zero and 12.7 kOe. In this range, the heat capacity is characterized by a broad anomaly near 1 K and no field dependence. The dc magnetization, which was measured from 1.7 to 300 K and with magnetic fields up to 50 kOe, indicates an effective number of one 25.6 μ B localized moment for approximately every 240 Mn atoms. The magnetic susceptibility follows the Curie-Weiss law for T ≧ 15 K, while a spin-glass-like ordering is observed at 7.8 K. Comparisons are made with similar measurements previously reported for the related quasicrystalline icosahedral (I-phase) Al 8 0 Mn 2 0 alloy.