Pressure–Volume Relationship of a Au–Al–Yb Intermediate Valence Quasicrystal and Its Crystalline Approximant

Synchrotron X-ray diffraction experiments of an icosahedral Au–Al–Yb quasicrystal and its 1/1 crystalline approximant were performed under quasi-hydrostatic pressure up to approximately 20 GPa at room temperature. Their pressure–volume compression curves are similar each other, show a monotonic decrease, which indicates the structural stability these compounds pressure. The bulk moduli determined be B0 = 105.1(8) for 108.1(7) approximant. These values explained by composition-weighted average constituent element.