Magnetic Properties of an Icosahedral Phase of Ga-Mg-Zn Alloy

Magnetic properties of two kinds of Ga-Mg-Zn alloy samples were studied. One is Ga20Mg40Zn40 icosahedral phase which was thermally stable below about 615 K, the other is Ga18.5Mg41.5Zn40 alloy which exhibited amorphous-like X-ray diffraction pattern with no sharp peaks. The icosahedral phase showed a linear relationship between the magnetic susceptibility and the square of temperature. The improvement of the specimen quality resulting from heat treatment made the temperature dependence enhanced and the paramagnetism reduced. The amorphous-like sample did not show the temperature dependence of the magnetic susceptibility. These facts afford the experimental evidence that, in terms of Pauli paramagnetism, the electronic density of states at Fermi level of the icosahedral phase is strongly affected by the band-structure originating from the quasiperiodicity.