Analysis of composition dependence of formation of ternary bulk metallic glasses from crystallographic data on ternary compounds

The composition dependence of formation of ternary bulk metallic glasses (BMGs) has been analyzed with crystallographic data concerning 16873 ternary compounds with a composition triangle named L-M-S diagram for relative atomic size of constituent elements of L (Large), M (interMediate), and S (Small). As well as ternary compounds containing Cu₂Mg, Fe₂P and C₆Cr₂₃ types, three types of ternary BMGs characterized by the relative atomic size of the main element of L- (La-, Zr-, Pd- and Ca-based BMGs), M- (Fe- and Mg-based BMGs) and S-types (Cu-based BMGs) are plotted in the L-M-S diagram. The L-M-S diagram with plots of all ternary compounds reveals a general tendency that the ternary compounds are frequently formed in the S-rich corner as compared to L- and M-rich corners. The L-M-S diagram shows that Fe₂ P and C₆Cr₂₃ type compounds directly affect the formation of M-type BMGs and also possibly influence the formation of the L-type BMGs. The high glass-forming ability of La-, Zr- and Ca-based BMGs is due to features of their composition regions in the L-M-S diagram wherein ternary compounds infrequently appear and anti-Laves relationship to Cu₂ Mg type compounds holds in ternary systems.