EXAFS STUDY OF NEAR-NEIGHBOR STRUCTURE ABOUT Mn ATOM IN QUASICRYSTALLINE Al-Mn ALLOY
用EXAFS测定准晶Al-Mn合金中Mn原子的近邻结构

EXAFS spectra (including near edge X-ray absorption spectra) have been measured at the Mn K edge of i-Al6Mn, i-Al4Mn and crystalline Al6Mn. The first near-neighbor structures about Mn atom of the i-Al6Mn and i-Al4Mn have been studied and discussed. We found that the average distance between Al and Mn atoms is about 2.52 angstrom in quasicrystalline phases and its shorter than that in crystalline Al6Mn. The coordination number around Mn atom is about 5 in quasicrystalline phases and is less than that in crystalline Al6Mn. The structure unit may be the same as in i-Al6Mn and i-Al4Mn. It is reasonable that the Mn atoms distribute on the surface of the unit.