Abstract
The composition range for the formation of a 1/1 cubic approximant phase to icosahedral quasicrystal has been investigated in various Sc based alloys of Sc-Rh-TM (TM: transition metal) type. The composition area of the approximant phase differs depending on the TM element and can be classified into three groups: in one group it extends roughly along a Rh constant line, in another it extends roughly along a Sc constant line and in the other it extends two-dimensionally in the diagram. The shape of the composition area correlates well with the position of the TM element in the periodic table, although it has no apparent correlation with the number of valence electrons per atom ratio (e/a ratio).
Acknowledgements
We thank Dr. R. Tamura of Dept. of Mater. Sci. and Tech. of Sci. Univ. of Tokyo for valuable comments and discussion. This work was financially supported by Core Research in Environmental Science and Technology (CREST), Japan Science and Technology Corporation.