Electronic, magnetic, elastic and transport properties of the quaternary Heusler compounds CoFeMSi (M = Cr, Mn)

Abstract

Ab-initio calculations were used to investigate the structural, electronic, magnetic, elastic, and thermoelectric properties of CoFeCrSi and CoFeMnSi (noted by CoFeMSi were M = Cr, Mn) as a quaternary Heusler compounds (QHC). Fist-principles calculations are performed via the generalized gradient approximation (GGA + U) for the electronic exchange–correlation functional. The results revealed that CoFeMSi (M = Cr, Mn) exhibit remarkable half-metallic ferromagnetism (HMF) with wide gaps, respectively, of 0.465 eV and 0.503 eV. The analysis of electronic and magnetic properties indicate that the major contribution in the total magnetic moments is from Mn or Cr atom in the both compounds. As well, the various elastic parameters have been computed that indicate the plasticity and ductility behavior in the studied compounds. In addition, thethermoelectric properties of these QHCs versus chemical potential have been investigated for selected temperature. At room temperature around Fermi level, the maximum values of the Seebeck coefficient (S) are 791.85 μV/K and 849.17 μV/K, for CoFeCrSi and CoFeMnSi, respectively. The merit factor (ZT) is found close to the unit leading to promising materials for washed heat recovery.