High-pressure Powder X-ray Diffraction Study of Cu₅Si and Pressure-driven Isostructural Phase Transition

Journal Article · Mon Dec 03 04:00:00 EST 2012 · Philosophical Magazine Letters

DOI:https://doi.org/10.1080/09500839.2012.745017· OSTI ID:1229116

Li, C. ^[1]; Yu, Z. ^[2]; Liu, H. ^[3]; Lu, T. ^[3]

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1. Harbin Inst. of Technology (China); Brookhaven National Lab. (BNL), Upton, NY (United States)
2. Argonne National Lab. (ANL), Argonne, IL (United States); Harbin Inst. of Technology (China)
3. Harbin Inst. of Technology (China)

The structural behaviour of Cu₅Si under high-pressure (HP) has been studied by angular dispersive X-ray diffraction up to 49.9 GPa. The experimental results suggest that a pressure-induced isostructural phase transition occurs around 13.5 GPa as revealed by a discontinuity in volume as a function of pressure. The lattice parameter decreases with the pressure increasing for both low-pressure (LP) and HP phases of Cu₅Si. However, a plot of the lattice parameter vs. pressure shows the existence of a plateau between 11.7 and 15.3 GPa. The bulk moduli, derived from the fitting of Birch–Murnaghan equation of state, are 150(2) GPa and 210(3) GPa for the LP phase and the HP phase of Cu₅Si, respectively. A change in the electronic state of the copper is assumed to govern the observed structural phase transition.

• Research Organization: Brookhaven National Laboratory (BNL), Upton, NY (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
• OSTI ID: 1229116
• Report Number(s): BNL--111191-2015-JA
• Journal Information: Philosophical Magazine Letters, Journal Name: Philosophical Magazine Letters Journal Issue: 2 Vol. 93; ISSN 0950-0839
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
Cu-Si
crystal structure
crystal symmetry
high-pressure studies
intermetallic compounds
phase transitions
x-ray diffraction