Theoretical study of phase stability, magnetization and lattice vibrations of Fe23CB6 structure with Cr23C6 prototype

The new intermetallics Fe23CB6 have been studied to ascertain the effect of ternary element C on the phase stability and site preference. Fe23CB6 may form with Cr23C6 prototype structure, and the carbons atoms are positioned at 4a sites. The calculated lattice constants are found to agree with report in literatures. We have calculated the magnetic moments of Fe22NiB6, Fe23C6, Fe23B6 and Fe23CB6 compounds. Furthermore, the total and partial phonon densities of states are evaluated first for Fe23C6, Fe23B6 and Fe23CB6. The analysis of the inverted potentials explains qualitatively the contributions of different atoms to the vibrational modes.

Pair potentials based on ab initio calculations and on the lattice-inversion method have been used to calculate the structural properties of a new compound Fe23CB6. The results show that Fe23CB6 possess the Cr23C6 prototype of structure, and the carbons atoms are positioned at 4a sites in Fe23CB6 compound. The calculated lattice constants are similar to observed results from literatures. Further, the stability of the structure is further confirmed through molecular dynamic simulations at different temperatures. In addition, we have calculated the magnetic moments of Fe22NiB6, Fe23C6, Fe23B6 and Fe23CB6 compounds. Furthermore, the phonon densities of states (DOS) of these complex compounds are evaluated for the first time. Figure optionsDownload as PowerPoint slideHighlights
► New crystal structure Fe23CB6 predicted via pair potentials based on lattice-inversion method.
► Phase stability and site preference substitution of Fe23−xTxB6 are analysed.
► The magnetic moments of Fe22NiB6, Fe23C6, Fe23B6 and Fe23CB6 are calculated.
► The phonon densities of states of Fe22TB6, Fe23C6, Fe23B6 and Fe23CB6 are first evaluated.