Electronic structure and fermiology of LaFe2Ge2

The Density functional theory has been used to investigate the electronic structure properties of layered ternary compound LaFe2Ge2. The main trends in band structure, Fermi level, DOS, and charge density for the Fe2Ge2 layer with nonmagnetic La atom have been analyzed. The electron charge density has shown a hybridization between Fe-3d and Ge-4p causing the splitting of Fe-3d holes and electrons states which increases the Fe magnetic moment. The DOS of Fe-3d and Ge-4p orbitals has indicated that only a small set of 3d and 4p electronic states has been hybridized just under Fermi energy. Additionally, most of Fe-3d and Ge-4p states have been hybridized in the energy range from - 5 eV to - 2 eV. The magnetic moment of LaFe2Ge2 is 4.96 mu(B) per formula unit where a localized magnetic moment of 2.54 mu(B) is associated with the Fe muffin-fin sphere. The Fe-4s and Ge-4s, 4p bands crossing Fermi level have formed a complicated Fermi surface for majority channel, whereas the spin down Fermi surface consists of simple narrow tubes.