Atomistic study on the site preference and lattice vibration of Gd3−xYxCo29T4B10 (T=Al and Ge)

• The application of the pair potentials obtained from lattice-inversion method.
• The lattice vibrations for Gd3−xYxCo29T4B10 (T=Ge and Al) are first evaluated.
• The Y atoms should prefer the 2b site of Gd3−xYxCo29T4B10 compounds.
• The total and partial phonon densities of states are evaluated for the Gd3−xYxCo29T4B10 compounds with the tetragonal structure.
• A qualitative analysis is carried out with the relevant potentials for the vibrational modes.

The effects of the Y substitution for Gd on the structural stability and the site preference of intermetallics Gd3−xYxCo29T4B10 (T=Al and Ge) are studied by using a series of interatomic pair potentials. The calculated results show Y can stabilize Gd3−xYxCo29T4B10 with the tetragonal structure, and Y substitute for Gd with a strong preference for the 2b sites. The calculated lattice parameters are in good agreement with the experimental data. Furthermore, the total and partial phonon densities of states are evaluated for the Gd3−xYxCo29T4B10 compounds with the tetragonal structure. A qualitative analysis is carried out with the relevant potentials for the vibrational modes, which makes it possible to predict some properties related to lattice vibration.

The lattice cell of Gd3Co29T4B10 consists of 92 atoms, or two Gd3Co29T4B10 formula units, with fourteen distinct kinds of site. Rare-earth atoms occupy 2b and 4d sites, Co atoms occupy the Co1(2c), Co2(8i1), Co3(8i2), Co4(8i3), Co5(8j1), Co6(8j2) and Co7(16k), T atoms occupy the T(8i) sites, and B atoms occupy the B1(2c1), B2(2c2), B3(8i) and B4(8j) sites.Figure optionsDownload as PowerPoint slide