Interlayer exchange coupling: Preasymptotic corrections

In the asymptotic limit, the interlayer exchange coupling decays as $D^{-2}$, where $D$ is the spacer thickness. A systematic procedure for calculating the preasymptotic corrections, i.e., the terms of order $D^{-n}$ with $n \ge 3$, is presented. The temperature dependence of the preasymptotic corrections is calculated. The results are used to discuss the preasymptotic corrections for the Co/Cu/Co(001) system.