Proximity-induced short-range spin density wave order in Fe/Cr multilayers

¹ Laboratoire d'Etudes des Propriétés Electroniques des Solides Associated with Université Joseph Fourier, CNRS BP 166, 38042 Grenoble Cedex 9, France
² Russian Research Center "Kurchatov Institute" Kurchatov Square, 123182 Moscow, Russia

Received: 22 January 2001
Accepted: 19 July 2001

Abstract

To describe the magnetic phase diagram of Fe/Cr multilayers we propose an approach based on the Ginzburg-Landau expansion of the free energy in terms of a spin density wave (SDW) order parameter which is determined self-consistently. This approach shows the existence of short-range order with a characteristic width D close to the interfaces. Although not homogeneous this phase resembles the commensurate SDW identified in neutron experiments and determines the observed high-temperature transition temperature T₁. The dependence of T₁ on the Cr thickness L is in agreement with the experimental behaviour and the length 2D can be identified with the critical Cr thickness for the existence of the incommensurate SDW.