THEORETICAL STUDY OF PHASE FORMING, MAGNETIZATION AND LATTICE VIBRATIONS OF Fe23-xTxB6(T = Cr, Mn, Ni, C), Fe23 C6, Fe23B6 AND Fe23CB6

We present a theoretical investigation on the phase stability, site preference and lattice constants of Fe23-xTx B6(T = Cr, Mn, Ni, C), Fe23C6 and Fe23CB6. The calculated results show that in Fe23-xTxB6 the Cr, Mn or Ni atoms prefer 4a sites. Fe23CB6 may form with Cr23C6 prototype structure, and the carbon 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 Fe23C6, Fe23B6 and Fe23CB6 compounds. Furthermore, the total and partial phonon densities of states are evaluated first for these compounds. The analysis of the inverted potentials explains qualitatively the contributions of different atoms to the vibrational modes.