  We study the combined effect of temperature and disorder in the spacer on the
interlayer exchange coupling. The temperature dependence is treated on ab
initio level. We employ the spin-polarized surface Green function technique
within the tight-binding linear muffin-tin orbital method and the Lloyd
formulation of the IEC. The integrals involving the Fermi-Dirac distribution
are calculated using an efficient method based on representation of integrands
by a sum of complex exponentials. Application is made to
Co/Cu_{100-x}M_x/Co(001) trilayers (M=Zn, Au, and Ni) with varying thicknesses
of the spacer.
