Reversible polyamorphic transitions in Ce65.5Al10Cu22.5Co2 metallic glass

• A reversible polyamorphic transition was discovered in Ce65.5Al10Cu22.5Co2 MGs.
• The alloy displays a strong hysteresis in polyamorphic-phase transition.
• The transition is strongly correlated 4f-electron delocalization of Ce metal.
• Hysteresis behavior was caused by the densification of Ce-based MGs.

We report here on a reversible polyamorphic transition in Ce65.5Al10Cu22.5Co2 metallic glasses under high pressure investigated by in situ angle-dispersive x-ray diffraction. The alloy is found to display a strong hysteresis in polyamorphic-phase transition upon application and subsequent release of pressure. We demonstrate that, the hysteresis behavior was caused by the densification of Ce-based metallic glasses under high pressure, which was resulted by the irreversible annihilation of free volume and elastic volume change. The transition is strongly correlated 4f-electron delocalization of Ce metal. These results provide a guidance for understanding mechanism of polyamorphic-phase transition in metallic glasses.

Pair distribution functions, g(r), of Ce65.5Al10Cu22.5Co2 MGs obtained during compression and decompression. This confirms that amorphous to amorphous transition indeed exists in Ce-based MGs, and the alloy displays a strong hysteresis in polyamorphic-phase transition upon application and subsequent release of pressure.Figure optionsDownload as PowerPoint slide