Magnetization reversal and exchange bias effects in hard/soft ferromagnetic bilayers with orthogonal anisotropies

The magnetization reversal processes are discussed for exchange-coupled ferromagnetic hard/soft bilayers made from Co[subscript 0.66]Cr[subscript 0.22]Pt[subscript 0.12] (10 and 20 nm)/Ni (from 0 to 40 nm) films with out-of-plane and in-plane magnetic easy axes respectively, based on room temperatur...

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Bibliographic Details
Main Authors: Ross, Caroline A., Navas, David Otero, Torrejon, J., Beron, F., Redondo, C., Batallan, Francisco, Toperverg, P., Devishvili, Anton, Sierra, B., Castano, F., Pirota, K. R
Other Authors: Massachusetts Institute of Technology. Department of Materials Science and Engineering
Format: Article
Language:en_US
Published: IOP Publishing 2013
Online Access:http://hdl.handle.net/1721.1/76668
https://orcid.org/0000-0003-2262-1249
Description
Summary:The magnetization reversal processes are discussed for exchange-coupled ferromagnetic hard/soft bilayers made from Co[subscript 0.66]Cr[subscript 0.22]Pt[subscript 0.12] (10 and 20 nm)/Ni (from 0 to 40 nm) films with out-of-plane and in-plane magnetic easy axes respectively, based on room temperature hysteresis loops and first-order reversal curve analysis. On increasing the Ni layer thicknesses, the easy axis of the bilayer reorients from out-of-plane to in-plane. An exchange bias effect, consisting of a shift of the in-plane minor hysteresis loops along the field axis, was observed at room temperature after in-plane saturation. This effect was associated with specific ferromagnetic domain configurations experimentally determined by polarized neutron reflectivity. On the other hand, perpendicular exchange bias effect was revealed from the out-of-plane hysteresis loops and it was attributed to residual domains in the magnetically hard layer.