Study of melt-grown quasicrystalline samples in the Cd-Yb and Al-Cu-Fe systems

The regimes of preparation of bulk samples of the quasicrystalline phase in the Cd-Yb and Al-Cu-Fe systems have been investigated. A thermodynamically stable quasicrystalline phase Cd_5.7Yb and its approximant Cd₆Yb with a high degree of texture along the cooling axis have been obtained. X-ray diffraction analysis made it possible to reveal changes in the structure and phase composition of bulk samples with variation in the melting temperature and annealing for different methods of sample preparation. It is shown that the presence of a temperature gradient along the furnace axis significantly affects the volume of the quasicrystalline phase. It is established that, with a decrease in the volume of the quasicrystalline phase mixed with the crystalline phase, the character of the temperature dependence of resistivity changes from the semiconductor type to the metallic type and the microhardness decreases according to a linear law.