First-Principles Calculation and Experimental Investigations on Full-Heusler Alloy Co $_{2}$ FeGe

First-principles calculation has been carried out for the full Heusler alloy Co₂FeGe within the scheme of density functional theory using plane-wave self-consistent field method. The spin polarized band structure does not show any energy gap at the Fermi level for both up and down spin electrons. Atom resolved magnetic moment on each site was observed to be 1.3 mu_B (Co), 2.9 mu_B (Fe), and 0.0 mu_B (Ge). X-ray diffraction studies reveal a B2-type structure for the bulk sample and cubic L2₁ structure for the melt-spun ribbons. The lattice parameter value for the ribbon is 5.736 Aring, and its Curie temperature is around 981 K. The magnetic moment per formula unit at 5 K was observed to be 5.74 mu_B. The low temperature data ( < 100 K) follows the relationrho = rho₀ + AT² + BT^4.5 , indicating the presence of one magnon spin-flip scattering.