Investigation of thermoelectric properties of half-metallic Co₂MnGe by using first principles calculations.
By combining the electronic structures obtained from first principles calculations with Boltzmann transport theory we have investigated the electronic, magnetic and transport properties of the Co2MnGe Heusler compound. The density of state plots, dispersion curves and the total energy of paramagnetic and ferromagnetic (FM) phases clearly show the half-metallic FM ground state for the compound, with an indirect band gap of about 400 meV in the minority spin channel. It has an integer value of the magnetic moment equal to 5 μ(B). In the FM phase a very large value (∼ 550 µV K(-1)) of the Seebeck coefficient (S) is obtained for down-spin electrons due to the existence of an almost flat conduction band along X in the Γ direction. The two-current model has been used to find the total S and the obtained value is about 10 µV K(-1). The calculated values of the Seebeck coefficient, resistivity and electronic thermal conductivity show nice agreement with the experimental results.
School of Engineering, Indian Institute of Technology Mandi, Kamand - 175005, Himachal Pradesh, India.
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D003035:Cobalt / Q000737:chemistry*; D004553:Electric Conductivity; D004583:Electrons; D005857:Germanium / Q000737:chemistry*; D008280:Magnetics; D059346:Magnets; D008345:Manganese / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry*; D011789:Quantum Theory; D013814:Thermal Conductivity
D010087:Oxides; D005857:Germanium; D003035:Cobalt; D008345:Manganese; C060728:cobalt oxide