Room temperature activated slow β relaxation and large compressive plasticity in a LaCe-based bulk metallic glass

Activation of the β relaxation of metallic glasses is usually related to the activation of the structure units which correlates with the activation of shear transformation zones. In the present work, a pronounced slow β relaxation behavior was observed around ambient temperature in (La₂₅Ce₇₅)₆₅Al₁₁Co₂₄ metallic glass. Based on the compression tests at 223 K and 300 K, the results demonstrated that compression achieves large compressive plasticity with true plastic strain over 160% at room temperature, while the compressive plastic strain less than 1% at 223 K. From the perspective of structural heterogeneity, the (La₂₅Ce₇₅)₆₅Al₁₁Co₂₄ metallic glass provides a model alloy to probe the mechanisms of deformation at room temperature induced shear transition behaviors.