Glass-to-glass transitions are useful for us to understand the glass nature, but it remains difficult to tune the metallic glass into significantly different glass states. Here, we have demonstrated that the high-entropy can enhance the degree of disorder in an equiatomic high-entropy metallic glass NbNiZrTiCo and elevate it to a high-energy glass state. An unusual glass-to-glass phase transition is discovered during heating with an enormous heat release even larger than that of the following crystallization at higher temperatures. Dramatic atomic rearrangement with a short- and medium-range ordering is revealed by in-situ synchrotron X-ray diffraction analyses. This glass-to-glass transition leads to a significant improvement in the modulus, hardness, and thermal stability, all of which could promote their applications. Based on the proposed high-entropy effect, two high-entropy metallic glasses are developed and they show similar glass-to-glass transitions. These findings uncover a high-entropy effect in metallic glasses and create a pathway for tuning the glass states and properties.

Different from the reported results, multiphase (Fe_73.5Si_13.5B₉Nb₃Cu₁)_91.5Ni_8.5 nanocrystalline ribbons (CR-II) show much better degradation capability in Orange II than their metallic glass (MG) counterparts. CR-II ribbons have superior properties, such as high degradation capability, good durability and facile fabrication. In particular, high degradation efficiency could be expected even under an alkaline environment, while most reported zero-valent metals would only be available for acid or neutral environments. Galvanic cells between the α-Fe nanocrystals and intermetallics contribute to the high degradation capability of CR-II by accelerating the α-Fe nanocrystals to lose electrons, leading to the fracture of the azo bond (–NN–). Additionally, 3D nanoporous architectures and 3D flowerlike nanostructure sediments formed during the degradation process are also beneficial to the high degradation capability by promoting mass transport. These findings could provide new clues to design new materials with superior degradation capability and low cost for wastewater treatment.

Fracture mechanisms of metallic glasses are fundamentally different from that of crystalline alloys. Nano-voids formation and coalescence inside shear bands were believed to be one of the reasons causing the final failures. Although molecule dynamic simulations have successfully simulated cavitation in shear bands of brittle metallic glasses, direct experimental evidences are still rare. By carefully examining the shear bands of Pd_40.5Ni_40.5P₁₉, nano-voids and their coalescence have been observed in the center-diffused region of shear bands. It is experimentally confirmed that nano-voids formation and their coalescence into large voids within shear bands is one of fracture mechanisms of metallic glasses.