Understanding Czochralski growth of decagonal AlCoCu

Abstract

Czochralski growth of decagonal AlCoCu was investigated using spontaneous nucleation as well as AlCoNi seeds of different orientations. Contrary to all knowledge gained from the growth of large single crystals in the Al–Co–Ni system, growth of AlCoCu quasicrystals proved to be much more complicated. Second-phase inclusions were found to be the main problem, resulting in various features affecting regular crystal growth. Even at extremely low pulling rates, this could only be solved by growing along the two-fold [10000]-direction. Finally, large-grain Al_67.5Co_20.0Cu_12.3 single crystals, having a rather homogeneous elemental distribution, were successfully grown from the initial melt of composition Al₆₆Co₁₀Cu₂₄.

Acknowledgement

Financial support by the Deutsche Forschungsgemeinschaft under contract Gi 211/3 is gratefully acknowledged.

Notes

Present address: Ames Laboratory, Iowa State University, Ames, IA 50011, USA

Additional information

Notes on contributors

L. Zhang†

Present address: Ames Laboratory, Iowa State University, Ames, IA 50011, USA