Tuning material properties via disorder: From crystalline alloy to metallic glass

Pathways to tune the electronic, chemical, mechanical, and optical properties of solids without modifying their composition represent a new paradigm in the design of functional and sustainable materials. The level of structural disorder – from perfectly crystalline to fully amorphous – for example, induces remarkable changes in material properties. Typically, disorder is introduced by altering the composition of a material, adding to the misconception that these two properties cannot be decoupled. Here, we demonstrate that striking differences in the optical, electronic, and corrosion properties of CuZr are achieved by deliberately and reproducibly engineering the level of structural disorder in pulsed laser deposited thin films of a constant composition. This approach allows tuning the structure of CuZr from polycrystalline to fully amorphous, switching the nature of charge transport from metallic to semiconductor-like, the optical properties in the visible regime from opaque to transparent, and the corrosion behavior in air from mixed oxidation to the formation of a protective Zr oxide overlayer. Our results highlight the tunability of structural disorder in alloys and its remarkable effect on material properties, providing the opportunity to design sustainable functional materials based on customizing properties beyond their composition.