Zr60Al15(Ni,Cu)25 noncrystalline alloys created by referring to ionic arrangements of a garnet structure with molecular dynamics simulations based on a plastic crystal model

The Zr60Al15(Ni,Cu)25 noncrystalline alloys with their initial crystalline states from the ionic arrangements of a Fe3Al2Si3O12 garnet structure were created with molecular dynamics simulations based on a plastic crystal model (MD-PCM). The analyses with pair-distribution function revealed that the randomly-rotated octahedral clusters around the Cu sites or tetrahedral clusters around the Ni sites and subsequent annealing with MD-PCM make the Zr60Al15(Ni,Cu)25 crystalline alloys to vitrify. The interference function indicated that the Zr60Al15Ni25 noncrystalline alloy created through rotating operation for the octahedral clusters gives the best fit with the experimental data in an as-quenched state. Crystallographic analyses indicated that the prototype of the garnet structure, Weaire–Phelan (A15) structure, gives inhomogeneous Wigner–Seitz cell for the solute elements and an optimized heat of mixing for atomic pairs in the Zr60Al15(Ni,Cu)25 noncrystalline alloys. These crystallographic features due to Weaire–Phelan structure are a reason for the Zr60Al15(Ni,Cu)25 alloys to have high glass-forming ability.