Review on distorted face-centered cubic phase in yttrium via genetic algorithm

^†This paper was presented at the LIIth European High Pressure Research Group (EHPRG 52) Meeting in Lyon (France), 7–12 September 2014.

Abstract

We present two distorted face-centered cubic (dfcc) structures of yttrium under high pressure, which have been found by a first-principles genetic algorithm technique. The structures are a tetragonal P4₃ (dfcc-I) and a triclinic P1¯ (dfcc-II), formed by slight distortions from a trigonal R3¯m structure reported as the dfcc phase earlier. The enthalpy difference between the two dfcc structures is less than 0.2 mRy/atom, and dfcc-I is marginally more stable than dfcc-II in lower pressure region. The enthalpy comparison among candidate structures indicates the structural phase transitions into dfcc-I at 41 GPa, into dfcc-II at 81 GPa, and into an orthorhombic Fddd structure at 106 GPa.

Keywords:

• first-principles calculation
• genetic algorithm
• structure searching
• yttrium

Acknowledgements

The work was supported by the Japan Society for the Promotion of Science (JSPS) through its ‘Funding Program for Next Generation World-Leading Researchers (NEXT Program)’ No. GR068 and ‘KAKENHI’ Nos. 25800218 and 2600006.

Notes

^† This paper was presented at the LIIth European High Pressure Research Group (EHPRG 52) Meeting in Lyon (France), 7–12 September 2014.