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P. Dróżdż

Publications and source records attributed to P. Dróżdż.

3 recordsLinked to original sources

Imprinting of Antiferromagnetic Vortex States in NiO-Fe Nanostructures

Magnetic vortices are topological spin structures frequently found in ferromagnets, yet novel to antiferromagnets. By combining experiment and theory, we demonstrate that in a nanostructured antiferromagnetic-ferromagnetic NiO(111)-Fe(110) bilayer, a magnetic vortex is naturally stabilized by magnetostatic interactions in the ferromagnet and is imprinted onto the adjacent antiferromagnet via interface exchange coupling. We use micromagnetic simulations to construct a corresponding phase diagram of the stability of the imprinted antiferromagnetic vortex state. Our in depth analysis reveals that the interplay between interface exchange coupling and the antiferromagnet magnetic anisotropy plays a crucial role in locally reorienting the Néel vector out-of-plane in the prototypical in-plane antiferromagnet NiO and thereby stabilizing the vortices in the antiferromagnet.

cond-mat.mes-hall↗

Tailoring the exchange bias effect by in-plane magnetic anisotropy

We report an unusual, non-monotonous dependence of the exchange bias on the thickness of the ferromagnetic layer in a ferromagnet/antiferromagnet bilayer system. We show that in epitaxial CoO/Fe(110) bilayers, the evolution of the Fe magnetic anisotropy, which drives the thickness-induced in-plane spin-reorientation process, controls the interfacial CoO spin directions in the 0-90 degrees range and, consequently, drastically modifies the magnitude of the hysteresis loop shift and its dependence on the thickness of the Fe layer. Our results present a new recipe for tailoring the exchange bias and antiferromagnetic spin structure by utilizing the spin-reorientation process that occurs in a ferromagnetic layer adjacent to an antiferromagnetic layer.

cond-mat.mes-hall↗

Switching of Co magnetization driven by antiferromagnetic-ferromagnetic phase transition of FeRh alloy in Co/FeRh bilayers

We show that Co spins in Co/FeRh epitaxial bilayers grown on W(110) switch reversibly between the two orthogonal in-plane directions as the FeRh layer undergoes temperature driven antiferromagnetic-ferromagnetic (AFM-FM) phase transition. Switching of Co magnetization is characterized by a hysteretic behavior owing to a temperature hysteresis of the AFM-FM transition in FeRh. The spin reorientation of Co is driven by the evolution interfacial exchange coupling to FeRh system across the AFM-FM process. Our results provide a new method of writing information purely by a local temperature change.

cond-mat.mes-hall↗