We present a spin resolved inverse photoemission study of Cr ultrathin film
s (up to few monolayers [ML]) grown on Ag(001) and Fe(001) at room temperat
ure. The magnetic properties of the films are strongly influenced by the di
fferent interaction with the substrates. For the Cr/Ag(001) system, where t
he chemical interaction of the overlayer with the substrate is very small,
no polarization dependence of the Cr features is observed, a finding which
can fit within the predicted antiferromagnetism of a Cr layer. For the case
of Cr/Fe(001), the Cr contribution is strongly polarized in the early stag
es of the interface formation (up to 2 ML) and then becomes gradually unpol
arized. (C) 2000 Published by Elsevier Science Ltd.