Exchange anisotropy in epitaxial NiO(001)-FCC Co bilayers

We have sputter deposited NiO-Co(100 Angstrom) bilayers on MgO(0 0 1) subst rates. NiO grows epitaxially on MgO at 800 degrees C and subsequently the r oom-temperature deposited 100 A-thick Co films have an FCC crystal structur e in epitaxy with the oxide underlayer. The magnetic properties of NiO-Co b ilayers are consistent with their structure exhibiting a four-fold magnetic anisotropy with easy axes along MgO(1 1 0) directions. Exchange anisotropy is evidenced by the increase of coercive field of the Co layer, asymmetry of the Co magnetization switching at room temperature and by the observatio n of exchange fields higher than 700 Oe at 5 It. (C) 1994 Elsevier Science B.V. All rights reserved.We have sputter deposited NiO-Co(100 Angstrom) bil ayers on MgO(0 0 1) substrates. NiO grows epitaxially on MgO at 800 degrees C and subsequently the room-temperature deposited 100 Angstrom-thick Co fi lms have an FCC crystal structure in epitaxy with the oxide underlayer. The magnetic properties of NiO-Co bilayers are consistent with their structure exhibiting a four-fold magnetic anisotropy with easy axes along MgO[1 1 0] directions. Exchange anisotropy is evidenced by the increase of coercive f ield of the Co layer, asymmetry of the Co magnetization switching at room t emperature and by the observation of exchange fields higher than 700 Oe at 5 K. (C) 1999 Elsevier Science B.V. All rights reserved.