A comparative study of a Heusler alloy Co2FeGe using LSDA and LSDA+U

We have calculated the on-site Coulomb repulsion (U) for the transition elements Co and Fe. To study the impact of Hubbard potential or on-site Coulomb repulsion (U) on structural and electronic properties the calculated values of U were added on GGA and LSDA. We performed the structure optimization of Co2FeGe based on the generalized gradient approximation (GGA and GGA+U). The calculation of electronic structure was based on the full potential linear augmented plane wave (FP-LAPW) method and local spin density approximation (LSDA) as well as exchange correlation LSDA+U. The Heusler alloy Co2FeGe fails to give the half-metallic ferromagnetism (HMF) when treated with LSDA. The LSDA+U gives a good result to prove that Co2FeGe is a HMF with a large gap of 1.10 eV and the Fermi energy (EF) lies at the middle of the gap of minority spin. The calculated density of states (DOS) and band structure show that Co2FeGe is a HMF when treated with LSDA+U.