In materials science, the yield point represents a critical threshold where a material transitions from elastic to plastic deformation. Below this point, materials like glasses can return to their original shape after stress is removed. Beyond it, however, the deformation becomes permanent, reflecting irreversible changes in the material’s internal structure. Understanding this transition is essential for designing materials that can withstand mechanical stress without failure, an important consideration in fields such as civil engineering, aerospace and electronics.

Despite its importance, the yield point in amorphous materials like glasses has remained difficult to study due to the challenges in precisely controlling and measuring the stress and strain required to trigger it. Traditional mechanical testing methods often lack the resolution needed to observe the subtle atomic-scale changes that occur during yielding.

In this study, the authors present a novel approach using X-ray irradiation to induce yielding in germanium-selenium glasses. This method allows for fine-tuned control over the elasto-plastic transition, enabling the researchers to systematically investigate the onset of plastic deformation. By combining experimental techniques with theoretical modelling, they characterize both the thermodynamic behaviour and the atomic-level structural and dynamical responses of the glasses during and after irradiation.

One of the key findings is that glasses processed through this method become stable against further irradiation, an effect that could be highly beneficial in environments with high radiation exposure, such as space missions or nuclear facilities. This work not only provides new insights into the fundamental physics of yielding in disordered materials but also opens up potential pathways for engineering radiation-resistant glassy materials.

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Theories of glass formation and the glass transition by J S Langer (2014)