Structural, electronic, magnetic and thermoelectric properties of full heusler alloys Co2YZ (Z = S, Ge, Se): A first principles calculation

Abstract

Density functional theory (DFT) calculations are used to find physical characteristics of full Heusler (FH) alloys Co2YZ (Z = S, Ge, Se). Full potential-linearized augmented plane wave (FP-LAPW) method within generalized gradient approximation (GGA) and Perdew-Burke-Ernzerhof functional is used. The results of phase stability have confirmed the stability of ferromagnetic (FM) phase as compared to anti-ferromagnetic (AFM), and nonmagnetic (NM) phases. The electronic properties show the half metallic (HM) character of Co2YS and Co2YSe by GGA. The role of on-site coulomb interaction (U) is also checked by GGA + U approach for Co2YGe which confirmed its HM nature. The band diagrams are in accordance to density of states (DOS). The total magnetic moment (MM) of all alloys is 3μB which is in agreement to Slater-Pauling Rule (SPR). The spin polarization (SP) indicated that these materials are completely spin polarized. The Seebeck coefficient (S) and electrical conductivity (σ) are also calculated and discussed.