Heat-induced effective exchange coupling in magnetic multilayers with semiconductors

Two ferromagnetic films separated by an amorphous semiconducting spacer lay er are exchange coupled across the spacer. The coupling is reversibly tempe rature dependent with a positive temperature coefficient making such layere d systems a 2-D realization of the concept of heat-induced magnetism. By st udying ferromagentic Fe layers separated by amorphous Si, Ge, or ZnSe layer s we explore the possibilities to generate such an effective exchange coupl ing and address the question of the mechanism responsible for it. (C) 1999 Elsevier Science B.V. All rights reserved.