General role of rare earth elements in dynamic characteristic of series of FeB-based bulk-glass-forming liquids

•A general role of rare earth elements in dynamic characteristic of series of FeB-based bulk-glass-forming liquids has been uncovered.•A negative correlation between the degree of dynamic transition F in melts and the glass-forming ability has been established in FeB-based bulk-glass-forming alloys.•The mechanism underlying the indistinct dynamic transition and the improved glass-forming ability of alloys induced by rare earth elements has been discussed.