Quasidiscontinuous change of the density correlation length at the fragile-to-strong transition in a bulk-metallic-glass forming melt

Many bulk-metallic-glass (BMG) forming melts undergo a rather abrupt fragile-to-strong transition (FST), at which density and local structure appear to change only continuously. In this study, we reproduce similar results for a ternary BMG former (Zr0.606Cu0.29Al0.104) using computer simulations. The results include a smooth evolution of radial distribution functions at small distances through the FST. However, the long-range density correlation length increases (quasi)discontinuously at the FST as revealed by an Ornstein-Zernikebased analysis of the radial distribution function. Likewise, the temperature derivative of a(Zr-Zr)(T) decreases (quasi)discontinuously at the FST. These observations add to the rich phenomenology of FSTs lacking a theoretical understanding.