Journal of Magnetism and Magnetic Materials 118 (1993) 365-372 North-Holland The Pd polarization at the Pd/Fe interface H. Nait-Laziz, S. Bouarab, zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA C. Demangeat zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJ IPCMS, lJMR46, Universite Louis Pasteur, 4 rue Blake Pascal, 67070 Strasbourg, France A. Mokrani Laboratoire de Physique du Solide Thkorique, 2, rue de la Houssini&e, 44072 Nantes, France and H. Dreysse Laboratoire de Physique des Solides, BP 239, 54506 Vandoeuvre-les-Nancy, France Received 8 April 1992; in revised form 19 June 1992 The electronic and magnetic properties of the ground state (T = 0 K) at the Pd/Fe(OOl) interface were investigated through the mean-field parameterized tight-binding method. Structurally, the Pd overlayers occupy the fee sites of the substrate, with a few percent expansion of the Pd-Pd distances as compared to the bulk fee Pd. We report results concerning deposition of n Pd layers on semi-infinite Fe. Ferromagnetic polarization of the Pd, layers are obtained up to n = 3. For n = 4, we have obtained ferromagnetic polarization of the nearest neighbour Pd overlayer but negative polarization for the three other planes. For n = 5, all the Pd atoms are polarized ferromagnetically unless the surface which has a quasi-zero magnetic moment. In the case of sandwiches Fe,,, /Pd, /Fe,,, or superlattices (Fe,Pd,), we investigate both ferromagnetic and antiferro- magnetic couplings between Fe films through the Pd spacer. For completeness we perform also total energy calculations in order to study the exchange coupling displayed by Celinski and Heinrich [J. Magn. Magn. Mater. 99 (1991) L25]. Similar trends are found: ferromagnetic coupling is shown to be stable until ‘n= 5 for Fe, /Pd, /Fe, sandwiches; antiferromagnetic coupling is however stable for n = 6. We discuss the importance of the interface roughness on this oscillation. zyxwvutsrqponmlkjih 1. Introduction Recent experiments have revealed that Fe/Pd multilayers show ferromagnetic coupling between Fe layers through Pd spacer up to 12 layers of the non-magnetic compound [1,2]. For a higher num- ber of Pd layers, a marginally small antiferromag- netic coupling is present. As it is well known, Pd Correspondence to: Dr. C. Demangeat, IPCMS, UMR46, Uni- versite Louis Pasteur, 4 rue Blaise Pascal, 67070 Strasbourg, France. Tel.: + 33-88-41-61-09; telefax: + 33-88-41-60-88; email: A04202@FRCCSC21.BITNET. is an incipient ferromagnet: a small percentage of Fe causes ferromagnetism and theoretically a paramagnetic-ferromagnetic (P-F) phase transi- tion occurs in bulk Pd with 6% lattice expansion [3-51. Furthermore, giant moments for Fe impu- rities in Pd have been observed [6]. Electronic structure calculations based on density functional theory and the Korringa-Kohn-Restocker Green’s function method yield a consistent pic- ture of the behavior of local moments of 3d impurities in Pd [7]. The calculated local impurity moments are in good agreement with experiment. However, less than 30% of the total induced 0304-8853/93/$06.00 0 1993 - Elsevier Science Publishers B.V. All rights reserved