Pressure-induced polyamorphism by quantitative structure factor and pair distribution function analysis in two Ce-based metallic glasses

• Published in: Journal of alloys and compounds 2017-02, Vol.695 (C), p.1180-1184
• Main Authors: Zhang, Linji, Sun, Fei, Hong, Xinguo, Wang, Junlong, Liu, Gang, Kong, Lingping, Yang, Hongwang, Liu, Xiuru, Zhao, Yong, Yang, Wenge
• Format: Article
• Language: English
• Subjects: High pressure; MATERIALS SCIENCE; Metallic glasses; Pair distribution function; Polyamorphism
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2016.10.246

We utilized the pair distribution function method to characterize the pressure-induced polyamorphic transition in Ce60Al20Cu20 and Ce55Al45 metallic glass at room temperature. Using synchrotron high-energy x-ray diffraction we collected scattering information from a large Q-space coverage, which in turn gave a high resolution g(r) that provided accurate local structure information. We observed a sudden change in compressibility and the nearest neighbor distance at 3.50–6.32 GPa for Ce60Al20Cu20 and 2.20–6.89 GPa for Ce55Al45. The origin of the volume collapse seemed to be pressure-induced qualitative changes in bond shortening that corresponded to different coordination spheres. The polyamorphic transitions in these two systems from low-density glass (LDG) to high-density glass (HDG) are associated with local atomic rearrangements. •Reliable S(Q) evolution under high pressure with large Q-space coverage is yielded.•Microstructure anomalous change during polyamorphism is clarified in two Ce-based MG.•Bond shortening near 4f electron delocalization seems origin of volume reduction.