Highly collective atomic transport mechanism in high entropy glass forming metallic liquids
Abstract Quasielastic neutron scattering (QENS) has been used to study the atomic relaxation process and microscopic transport mechanism in high entropy glass forming metallic (HE GFM) liquids. Self intermediate scattering functions obtained from the QENS data show unusually large stretching, which indicates highly heterogeneous atomic dynamics in HE GFM liquids. In these liquids, a group of atoms over a length scale of about 21 A diffuses collectively even well above the melting temperature. However, the temperature dependence of diffusion process in one of the HE GFM liquid is Arrhenius, but in the other HE GFM liquid it is non Arrhenius. Although the glass forming ability of these HE GFM liquids is very poor, the diffusion coefficients obtained from the QENS data indicate the long range atomic transport process is much slower than that of the best metallic glass forming liquids at their melting temperatures.