Structure and entropy control of polyamorphous transition in high-entropy metallic glasses

Recently, a putative phase transition has been discovered in metallic glasses that could lead to two distinct amorphous states. This phenomenon, known as polyamorphism, has garnered significant interest, but its origins are still not fully understood, and predicting which compositions may undergo this transition remains a daunting task. Here, through development and experimental analysis of 62 different high entropy metallic glasses (HEMGs), we have discovered that the polyamorphic transition of HEMGs is closely linked to the complexity of their parent crystalline phase. Specifically, the number of crystal phases observed in x-ray diffraction is consistently higher in compositions capable of exhibiting polyamorphism in HEMGs compared to those that cannot. Furthermore, we have identified a high-entropy effect that enhances the enthalpy of polyamorphous transition. These findings shed light on how the structure and entropy play a crucial role in controlling the polyamorphous transition and offer insights for materials design.