Kerr Effect Investigations of Magnetic Interlayer Interactions in EuS-PbS Multilayers

Abstract

ne K err m agnet ometr y w as employe d to study the temp erature dependence of magnet izati on and magnetic hysteresis loops in ferromagnetic Eu S{ PbS semiconductor multilayers in the temp erature range T = 3 35 K at low magnetic elds H 1 5 0 Oe. F or EuS{PbS /K C l( 100) structures w ith ultrathi n non-magnetic PbS spacer of 1 nm , w e obser ved a ma ximum on the temp erature dep endence of magnetizati on at low elds H 30 Oe. For higher elds, w e found for these structures a regular mean-eld-li ke increase in magnetization with decreasing temp erature. T he same regular beha vior w as also found for EuS{PbS/K C l structures w ith thicker PbS spacer, as w ell as for all EuS{PbS/ Ba F 2 (111) multilayers indep endently of spacer thickness. F or qualitati ve interpretation of these ndings, w e consider two magnetic contributions to the total energy of EuS{PbS multilayers : the Zeeman energy and the antif erromagnetic interlayer exchange coupling betw een ferromagnetic EuS layers via diamagnetic PbS spacer.