Large-sized quasi-crystals with continuously adjustable compositions

The quasi-crystal-forming alloys with adjustable compositions were prepared by element-addition to a pre-existing pure quasi-crystalline system. The protocol alloy Zr40Ti40Ni20 was chosen as the parent alloy, and beryllium was used as the additive element. The quasi-crystal forming ability was found to be enhanced with Be content within a wide composition range of (Zr40Ti40Ni20)100-xBex (0 ≤ x ≤ 16). A maximum size of up to 10 mm in diameter of pure quasi-crystalline rod was attained at a composition of (Zr40Ti40Ni20)84Be16. Structural analyses show that Be-addition continuously reduces the interplanar spacing. The mechanism of the enhanced quasi-crystal forming ability was also discussed.