Local Structure Study in Zr-Based Metallic Glasses

抄録

The local structure in the glassy state is investigated in the Zr₈₀Pt₂₀ and Zr₇₀Cu₃₀ binary and Zr₇₀Al₁₀Ni₂₀ ternary alloys in correlation with the quasicrystalline (QC) phase formation. The Zr₈₀Pt₂₀ alloy has a high QC-forming ability. It is easily formed in the as-quenched state with a considerably low cooling rate or by annealing the glassy alloy. The radial distribution function (RDF) and extended X-ray absorption fine structure (EXAFS) analysis clearly indicate the existence of icosahedral local structure around Pt atom. The Zr₇₀Cu₃₀ binary and Zr₇₀Al₁₀Ni₂₀ ternary metallic glasses have a QC-forming ability by the addition of a very small amount of noble metals such as Pd. We can also investigate the icosahedral local structure in these alloys. These results are realized that the icosahedral local structure can be applied as a dominant local atomic configuration in the supercooled liquid and/or glassy states in the QC-forming metallic glasses.