Impact of hybridization on metallic-glass formation and design

Abstract: The formation mechanism of glass at the atomic scale has been under debate over centuries. In this work, we demonstrate that hybridization, as manifested by Mott’s pseudogap, has a strong influence on the bond length as well as atomic packing, which can potentially tailor the formation of metallic glasses at microscopic time and length scales. A p–d orbital hybridization between the post-transition metal Al and the transition metal was shown by the ²⁷Al isotropic shifts and the spin–lattice relaxation time of Zr–Co–Al alloys using nuclear magnetic resonance. These bonds lead to a charge transfer between the specific atomic pairs and the shrinkage of interatomic distances. Such chemical bonding favors the formation of metallic glasses by introducing a string-like structure and further stabilizes metallic glasses via a reduction in the density of states at the Fermi level. Our work has implications for understanding the glass formation mechanism at the electronic level and may open up new possibilities on the design of glass from the perspective of atomic interactions.

https://doi.org/10.1016/j.mattod.2019.06.001