The mechanisms of plastic deformation of glassy solids and structural origin of $\beta$ relaxation are two fundamental issues. We provide compelling experimental evidence that the activation of shear transformation zones (STZs) and $\beta$ relaxations in metallic glasses are directly related, and the activation energy of the $\beta$ relaxation and the potential-energy barriers of STZs are nearly equivalent. Our results suggest an intrinsic correlation among potential STZs, $\beta$ relaxation, and the inhomogeneous atomic structure of metallic glasses, which has implications for understanding the deformation mechanism and structural origin of $\beta$ relaxation in glasses.

We report a close correlation between the dynamic behavior of serrated flow and the plasticity in metallic glasses (MGs) and show that the plastic deformation of ductile MGs can evolve into a self-organized critical state characterized by the power-law distribution of shear avalanches. A stick-slip model considering the interaction of multiple shear bands is presented to reveal complex scale-free intermittent shear-band motions in ductile MGs and quantitatively reproduce the experimental observations. Our studies have implications for understanding the precise plastic deformation mechanism of MGs.

Metallic glasses are commonly brittle, as they generally fail catastrophically under uniaxial tension. Here we show pronounced macroscopic tensile plasticity achieved in a La-based metallic glass which possesses strong $\beta$ relaxations and nanoscale heterogeneous structures. We demonstrate that the $\beta$ relaxation is closely correlated with the activation of the structural units of plastic deformations and global plasticity, and the transition from brittle to ductile in tension and the activation of the $\beta$ relaxations follow a similar time-temperature scaling relationship. The results have implications for understanding the mechanisms of plastic deformation and structural origin of $\beta$ relaxations as well as for solving the brittleness in metallic glasses.

Focusing on metallic glasses as model systems, we review the features and mechanisms of the β-relaxations, which are intrinsic and universal to supercooled liquids and glasses, and demonstrate their importance in understanding many crucial unresolved issues in glassy physics and materials science, including glass transition phenomena, mechanical properties, shear-banding dynamics and deformation mechanisms, diffusion and the breakdown of the Stokes–Einstein relation as well as crystallization and stability of glasses. We illustrate that it is an attractive prospect to incorporate these insights into the design of new glassy materials with extraordinary properties. We also outline important questions regarding the nature of β-relaxations and highlight some emerging research directions in this still-evolving field.

Electrocatalytic oxygen evolution reaction (OER) is key to several energy technologies but suffers from low activity. Leveraging the lattice oxygen activation mechanism (LOM) is a strategy for boosting its activity. However, this approach faces significant thermodynamic challenges, requiring high-valent oxidation of metal ions without compromising their stability. We reveal that high-entropy alloys (HEAs) can efficiently activate the LOM through synergistic multi-path electron transfer. Specifically, the oxidation of nickel is enhanced by this electron transfer, aided by the integration of weaker Co-O bonds, enabling effective LOM at the Ni-Co dual-site. These insights allow the design of a NiFeCoCrW_0.2 HEA that exhibits improved activity, achieving an overpotential of 220 mV at a current density of 10 mA cm⁻². It also demonstrates good stability, maintaining the potential with less than 5% variation over 90 days at 100 mA cm⁻² current density. This study sheds light on the synergistic effects that confer high activity in HEAs and contribute to the advancement of high-performance OER electrocatalysts.