Temperature dependence of the electronic transport in Al-Cu-Fe phases

The temperature dependences of the electronic conductivity and the thermoel ectric power are theoretically examined for the i-Al-Cu-Fe (1/1) approximan t in comparison with both crystalline omega -Al7Cu2Fe and amorphous Al84Fe1 6. Our study is based on ab initio results for the spectral curves which ar e obtained by means of the linear muffin-tin orbitals (LMTO) method and the Kubo-Greenwood formula. Thermopowers are calculated after the Mott formula . We show that a realistic variety of thermopower curves versus temperature results from small shifts of the Fermi energy in a narrow resistivity peak . A simple model of the energy-dependent resistivity is suggested which sup ports the interpretation of the thermopower curves. (C) 2000 Elsevier Scien ce B.V. All rights reserved.