A new crystalline phase, related to decagonal quasicrystals with non-central symmetry, is found in conventionally solidified Al70Co20Pd10and Al73Co22Pd5alloys. The new crystalline phase, which is called a W-phase hereafter, has an orthorhombic structure with lattice parameters a = 0.82nm, b = 2.06nm and c = 2.35 nm, and the space group Pmn21(No. 31). From electron diffraction and high-resolution electron microscopy observations of the W-phase, we propose a tentative structural model, which is constructed by modifying the structure of an Al-Ni-Co decagonal quasicrystal. A non-central symmetric decagonal quasicrystal with 0.4 nm periodicity is found in rapidly solidified Al70Co20Pd10and Al73Co22Pd5alloys. The structural relationships between the W-phase and decagonal quasicrystal are discussed.
|ジャーナル||Philosophical Magazine A: Physics of Condensed Matter, Structure, Defects and Mechanical Properties|
|出版ステータス||出版済み - 1 1997|
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