Eur. Phys. J. B 5, 203-214 (1998)
https://doi.org/10.1007/s100510050435

Interfacial polarisation effect on the interlayer couplings in Co/Rh sandwiches

¹ IPCMS-GEMME (UMR 46 CNRS-ULP.) , 23 rue du Loess, 67037 Strasbourg, France
² Siemens AG, ZFE T MR 1, P.O. Box 3220, 91050 Erlangen, Germany
³ SNCMP (UMS 819 CNRS-UPS.) , INSA, Complexe Scientifique de Rangueil, 31077 Toulouse, France

Corresponding author: ^a aziz@atlas.u-strasbg.fr

Received: 18 February 1998
Revised: 30 April 1998
Accepted: 29 May 1998
Published online: 15 September 1998

Abstract

The structural, magnetic and transport properties of Co/Rh sandwiches grown by ultra high vacuum evaporation and sputtering have been studied. High-energy electron diffraction observations during the growth reveal that both Co and Rh layers have been stabilised in the (111) fcc structure for the evaporated sandwiches. X-ray measurements performed on sputtered samples show a predominant fcc polycrystalline structure of the stacks with a preferential (111) texture. Magnetisation and magnetoresistance measurements show a very strong antiferromagnetic exchange coupling for thin Rh layers, reaching for 4.8 Å Rh, the strongest ever observed in exchange coupled systems. This value is in good agreement with the value of obtained by ab initio calculations for Co/Rh (hcp) superlattices. This is explained by the magnetic nature of the Co/Rh interfaces. Indeed, the variation of the measured saturation magnetisation as a function of the Co layer thickness shows no evidence of Co moment reduction for the Co atoms located at the interfaces, even for the very thin layers. The value of the preserved magnetic moments of the cobalt atoms at the interfaces is confirmed by ab initio calculations for Co/Rh superlattices taking the intermixing into account.