Multiple antiferromagnet/ferromagnet interfaces as a probe of grain-size-dependent exchange bias in polycrystalline Co/Fe50Mn50

Ultrawideband microwave noise filter: Hybrid antiferromagnet/ferromagnet exchange-coupled multilayers

“…Due to the overlap of several hysteresis loops with different exchange bias fields, the hysteresis loop manifests itself as a multiple-stage reversal. Similar behavior has previously been observed 16,17 for the exchange biased system using FeMn, where it was claimed that the bottom interface normally has a better unidirectional anisotropy constant and the reason for that is that the top interface is rougher than the bottom interface. 16 For the case of FeCo-MnIr multilayers since J K acting on each interface is identical the loop manifests itself as a single-shifted loop.…”

Controlling exchange bias in FeMn with Cu

“…4, 6, 7(a), and 7(c) in Ref. 6) The similarity suggests that these dependences might be primarily an intrinsic property of Cu/FeMn structures and might not be affected much by the presence of a FM. Moreover, the intrinsic exchange bias 23 (i.e., observed in an AF without a FM) might be determining the properties and the underlying mechanism of the exchange bias in AF-FM bilayers.…”

“…FeMn has a high T N (490 K for bulk FeMn, smaller for thin films) which results in exchange bias for bilayer FeMn-FM systems (e.g., FM ¼ NiFe) observed at and above room temperature. [3][4][5][6] It also had been shown that the presence of Cu next to FeMn modifies exchange bias in FeMn-FM systems. 7 Two types of samples are fabricated for these studies: The first consists of the 10-repeats superlattice of FeMn/Cu: Ta(5 nm)/[FeMn(t)/Cu(5 nm)] 10 /Ta(5 nm).…”

Relative-thickness dependence of exchange bias in bilayers and trilayers

“…This is the so-called ''pinning effect'' which is strongly affected by the AFM anisotropy and t AF . The pinning effect is strong above a critical t AF and weakened quite rapidly below that, eventually vanishes at another critical t AF [43][44][45]. Therefore, when t AF is lesser than t FM , the coercive fields at the first magnetization reversal are approximately identical and all close to the coercivity of pure FM bulk (see Fig.…”