Electronic structure, optical and magnetic properties of Co2FeGe Heusler alloy films

Optical properties of ferromagnetic half-metallic full-Heusler Co2FeGe alloy are investigated experimentally and theoretically. Co2FeGe thin films were obtained by DC magnetron sputtering and show the saturation magnetization at T = 10 K of m approximate to 5.6 mu(B)/f.u:, close to the value predicted by the Slater-Pauling rule. First-principles calculations of the electronic structure and the dielectric tensor are performed using the full-potential linearized-augmented-plane-wave method in the generalized gradient approximation (GGA) and GGA + U approximation. The measured interband optical conductivity spectrum for the alloy exhibits a strong absorption band in the 1-4 eV energy range with pronounced fine structure, which agrees well with the calculated half-metallic spectrum of the system, suggesting a near perfect spin-polarization in the material. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4752870]