Magnetic coupling in Fe/Cr/Fe(001) by spin-resolved empty-state spectroscopies

We report on a study of empty electronic states in Cr/Fe(001) films and a t rilayer as obtained by means of spin-polarized inverse photoemission and ab sorbed current spectroscopies: both spectroscopies are sensitive to the mag netic character of the Fe film. In relatively thick ( > 7 ML) Cr films, our data do not reveal any polarization dependence; on the contrary, in Fe/Cr/ Fe(001), we observe a reversal of the magnetic ordering of the Fe overlayer with respect to the buried Fe substrate as a function of the Cr spacer thi ckness, confirming the oscillating transition from FM to AF coupling betwee n the Fe layers. (C) 2000 Elsevier Science B.V. All rights reserved.