Effect of coexistence of similar elements La and Ce on formation of (La-Ce)-Al-Cu bulk metallic glasses

Bulk metallic glasses (BMGs) in pseudo-ternary (La-Ce)-Al-Cu system with high glass-forming ability (GFA) were synthesized based on the beneficial effect of the coexistence of similar elements La and Ce with similar atomic size and various valence electronic structures on GFA. With the coexistence of La and Ce in (La_xCe_1-x)₆₅Al₁₀Cu₂₅ system, bulk metallic glasses with diameters up to 12 mm can be produced by copper mold casting. Besides the high GFA, the (La_xCe _1-x)₆₅Al₁₀Cu₂₅ BMGs with x = 0.6 and 0.7 exhibit low glass transition temperature T_g around 362 K and wide supercooled liquid regions δT_x (δT_x = T_x - T_g, where T_x is the onset temperature of crystallization) of about 80 K. Compared with ternary La-Al-Cu and Ce-Al-Cu systems, significant improvement of GFA for the (La-Ce)-Al-Cu system is caused by the coexistence of similar elements La and Ce, and the mechanism is discussed from a thermodynamic viewpoint.