Modeling the structural, dynamical, and magnetic properties of liquidAl1−xMnx(x=0.14, 0.2, and 0.4): A first-principles investigation

Abstract

We report the results of first-principles molecular dynamics simulations of liquid ${\mathrm{Al}}_{1\ensuremath{-}x}{\mathrm{Mn}}_{x}$ alloys at three different compositions. The local structure as defined by the Bhatia-Thornton partial structure factors is found to display significant changes at $x=0.4$. In addition, a structural analysis using three-dimensional pair-analysis techniques evidences a fivefold symmetry around $x=0.14$, in agreement with the experimental quasicrystal-forming range, and an increasing complexity of the Frank-Kasper polytetrahedral symmetry around Mn atoms at $x=0.4$. We also examine the time evolution of the configurations at the three compositions in terms of the mean-square displacements and self-diffusion coefficients. Finally, we show a strong interplay between the structural changes and the evolution of the magnetic properties of the Mn atoms as a function of composition.