First-principles studies of modulated Co/Cu superlattices with strongly and weakly exchange-biased Co-monolayers leading to a ferrimagnetic ground state

Abstract

First-principles calculations have been performed in order to determine effective exchange integrals between strongly and weakly exchange-biased Co monolayers in the modulated CoCu${}_2$/CoCu${}_n$ superlattices. For $3\le n\le 6$ it has been found that the respective exchange integrals have opposite signs and differ for $n\ne 4$ from each other by one order of magnitude and for $n=4$ still by a factor of $\sim 1.7$. The obtained phase diagram, with all the relevant magnetic phases, shows that for the $n$-values considered, the ground state configuration is ferrimagnetic.

LaTex , 5 pages, plus 1 uuencoded .eps-file (to be called dia.eps)