Investigations on electronic, Fermi surface, Curie temperature and optical properties of Zr2CoAl

Abstract Using full-potential local-orbital minimum-basis along with spin-polarized relativistic Korringa-Kohn-Rostoker methods, we study the electronic, Fermi surface, Curie temperature and optical properties of Zr 2 CoAl alloy. The alloy with Li 2 AgSb and Cu 2 MnAl structures are compared in terms of magnetic properties, and the electronic structures in two structures are also discussed. According to the calculated electronic states, it finds that the Zr 2 CoAl with Li 2 AgSb structure is half-metallic ferromagnet with an integral magnetic moment of 2.00 μ B , meanwhile we also notice the d - d and p - d hybridizations are responsible for the formation of minority-spin gap, furthermore, the fat-bands are applied to discuss the mixture between d and p electrons in the vicinity of the Fermi level. The Fermi surfaces related to the valence bands are constructed, and it is found that the spin-up valence bands 26, 27 and 28 across the Fermi energy dominate the nature of electrons. By mapping the system onto a Heisenberg Hamiltonian, we obtain the exchange coupling parameters, and observe that the Zr(A)-Co(C) and Zr(A)-Zr(B) interactions provide a major contribution for exchange interactions. Based on the calculated exchange coupling parameters, the Curie temperature is estimated to be 287.86 K at equilibrium, and also the dependence of Curie temperature on lattice constant related to the tunable Curie temperature in Zr 2 CoAl alloy is studied. Finally, we report the optical properties of Zr 2 CoAl alloy, and present the photon energy dependence of the absorption, the optical conductivity and the loss function.