Quasi crystalline A1-Mn alloys: pressure induced crystallization and structural studies

Abstract

Irreversible, Pressure induced, quasicrystal-to-crystal transitions are observed for the first time in melt spun alloys at 4.9 GPa for Al₇₈Mn₂₂ and 9.3 GPa for Al₈₆Mn₁₄ by monitoring the electrical resistivities of these alloys as a function of pressure. Electron diffraction and X-ray measurements are used to show that these quasicrystalline phases have icosohedral point group symmetry. The crystalline phases which appear at high pressures are identified as h. c. p. for Al₇₈Mn₂₂ and orthorhombic for Al₈₆Mn₁₄.