The fragile magnetic structures of Fe/CeH2-delta multilayers

Fe/CeH2-delta multilayers exhibit at room temperature evidence of interlaye r exchange coupling. Subsequent Fe layers are either parallel or antiparall el to each other, depending on the Fe and CeH2-delta layer thickness. Howev er, when both layers have thickness larger than similar to 15 Angstrom, the antiferromagnetic structure becomes fragmented into domains laterally limi ted to a few microns, and the magnetic structures become very fragile. Smal l magnetic fields of a few Oersteds acting on the samples during growth ind uce helimagnetic configurations which coexist with antiferromagnetic coupli ng. The magnetic structures can be permanently destroyed by applying magnet ic fields larger than 150 Oe. (C) 2000 Elsevier Science B.V. All rights res erved.