High-resolution inelastic X-ray scattering measurements of an Al72Pd20Mn8 alloy above the melting point

The dynamic structure factor S(Q, ω) of the melt of an icosahedral quasicrystal, Al72Pd20Mn8, was measured at 1223 K near the melting point, Tm = 1140 K, for momentum transfers, Q, from 1.5 nm−1 to 5.55 nm−1 by means of inelastic X-ray scattering technique using synchrotron radiation at SPring-8. The composition of Al72Pd20Mn8 is a special one in AlPdMn ternary alloys, since icosahedral AlPdMn quasicrystal is formed directly from the melt. The acoustic mode was observed in the low Q region, and a sound velocity was estimated to be 4170 ± 100 m/s.