Formation and structure of icosahedral and glassy phases in MELT-SPUN AlSiMn.

X-ray scattering and electron transmission microscopy of melt- spun AlSiMn alloys reveal that the Al-Mn icosahedral phase itself can grow congruently over a range of composition varying from 16 to 20 at % Mn, and Si atoms substitute Al atoms selectively. The Q dependences of linewidth DELTA Q suggest that Hendrick- Teller disorder is dominant, however, the conventional disorders are also present. The glassy AlSiMn show a pronounced prepeak at Q sub p - 1.6angstroms sup -1 and a marked shoulder at low Q side of main peak (Q-3.0angstroms sup -1) suggesting a strong chemical order persisted in glassy alloys and crystalline intermetallic phases.