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The spectroscopy using synchrotron radiation is the advanced tool for materials characterization. In the current work we are reporting recent activity in this research field implemented at the 04BM (PEEM/XAS) beamline of the National Synchrotron Radiation Centre SOLARIS in Krakow, Poland. The beamline is designed to cover wide energy range of soft X-rays, which is well suited for a broad range of applications, including surface physics, material science and magnetism. The comparison of the experimental parameters and selected examples of the results achieved on the PEEM and XAS end stations is demonstrated.

We show that in a uniform thickness NiO(111)/Fe(110) epitaxial bilayer system, at given temperature near 300 K, two magnetic states with orthogonal spin orientations can be stabilized in antiferromagnetic NiO. Field-free, reversible switching between these two antiferromagnetic states is demonstrated. The observed phenomena arise from the unique combination of precisely tuned interface magnetic anisotropy, thermal hysteresis of spin reorientation transition and interfacial ferromagnet/antiferromagnet exchange coupling. The possibility of field-free switching between two magnetic states in an antiferromagnet is fundamentally interesting and can lead to new ideas in heat assisted magnetic recording technology.

We report on in-plane magnetic anisotropy in Au/Co/Fe(1 1 0) trilayers epitaxially grown on W(1 1 0). We observe single and double in-plane spin reorientation transitions that can be explained by the strongly non-monotonic dependence of magnetic anisotropy on the Co sublayer thickness. We point out the significant flexibility of the Au/Co/Fe(1 1 0) system for switching the in-plane easy axis of the magnetic anisotropy between the [ 1 1 ¯ 0 ] and [0 0 1] directions of the bcc(1 1 0) plane.

We show that in-plane to out-of-plane magnetization switching of a ferromagnetic layer can be driven by antiferromagnetic–ferromagnetic phase transition in a nearby FeRh system. For FeRh/Au/FeAu trilayers, the impact of the magnetic phase transition of FeRh onto the perpendicular magnetization of monoatomic FeAu superlattices is transferred across the Au spacer layer via interlayer magnetic coupling. The polar spin reorientation process of the FeAu spins driven by the magnetic phase transition in the FeRh reveals its major features; namely it is reversible and displays hysteresis.

A ferromagnet/antiferromagnet (FM/AFM) Fe/NiO bilayer was grown using molecular beam epitaxy on MgO(001) and Cr buffered MgO(001) substrates. X-ray linear dichroism measurements showed a dominating out-of-plane component for the NiO spins in Fe/NiO/MgO and an in-plane spin direction for NiO layers grown on the Cr buffer. Furthermore, systematic studies on the magnetic properties of Fe/NiO grown on the wedge-shaped Cr buffer revealed a continuous strain-induced spin reorientation transition from out-of-plane to in-plane NiO spin directions when the Cr thickness increased from 0 nm to 3.5 nm. The analysis of the in-plane magnetic structure of NiO in Fe/NiO/Cr showed a pronounced uniaxial anisotropy in thin AFM layers. The AFM spins are perpendicular to the Fe spins due to spin–flop interaction. These results demonstrate the feasibility of using strain and coupling with FMs to manipulate spin structures in NiO.

We report on the large coercivity enhancement in epitaxial Fe/FeRh bilayer grown on W(110). It is shown that the coercive field increases by almost an order of magnitude when the FeRh alloy undergoes a phase transition from the ferromagnetic to antiferromagnetic state. Analysis of temperature spin structure evolution of the FeRh alloy across the magnetic transition reveals that the observed coercivity enhancement is caused by the interfacial spin-flop coupling between Fe and the antiferromagnetic FeRh layer.

We report on the in-plane magnetic anisotropy in Au/Fe(1 1 0) and Co/Au/Fe(1 1 0) bi- and trilayers epitaxially grown on a W(1 1 0) single crystal. Magnetic surface anisotropy (MSA) exhibits a strongly non-monotonic, oscillatory behavior as a function of Au thickness. In the case of the Au/Fe(1 1 0) bilayers bi-periodic oscillations were observed and interpreted in terms of quantum well states that are affected by the alternating complete and in-complete atomic layers of Au. Thin bcc Co films grown on Au/Fe(1 1 0) bilayers strongly enhance MSA and for the Co/Au/Fe system magnetic anisotropy oscillates as a function of the Au spacer thickness due to the oscillatory interlayer coupling.

We studied the magnetic properties of 10 and 20 nm-thick, gold-capped FeRh layers grown on MgO(0 0 1). Whereas the majority of the FeRh film undergoes ferromagnetic–antiferromagnetic phase transition upon cooling, a small fraction of the FeRh system remains in the ferromagnetic state at low temperatures. This residual ferromagnetic phase located at the FeRh/MgO interface exhibits perpendicular magnetic anisotropy. Moreover, in the 10 nm-thick film, a small amount of the antiferromagnetic phase survives to high temperatures above the phase transition and probably originates from the epitaxial strains generated at the FeRh/Au interface.

We show that in a uniform thickness NiO(111)/Fe(110) epitaxial bilayer system, at given temperature near 300 K, two magnetic states with orthogonal spin orientations can be stabilized in antiferromagnetic NiO. Field-free, reversible switching between these two antiferromagnetic states is demonstrated. The observed phenomena arise from the unique combination of precisely tuned interface magnetic anisotropy, thermal hysteresis of spin reorientation transition and interfacial ferromagnet/antiferromagnet exchange coupling. The possibility of field-free switching between two magnetic states in an antiferromagnet is fundamentally interesting and can lead to new ideas in heat assisted magnetic recording technology.

In our study, we examined the chemical and magnetic properties of FeO in an epitaxial Fe/MgO(dMgO)/FeO trilayer for different MgO thicknesses, dMgO. Analysis of the chemical structure revealed a stoichiometry improvement in the FeO layer in Fe/MgO/FeO in comparison with a Fe/FeO bilayer. Furthermore, we showed that deposition of a subtle MgO layer at the Fe/FeO interface results in an enhanced exchange interaction between Fe and FeO. For dMgO = 1.4 A, we noted a 200% enhancement in the exchange bias in Fe/MgO/FeO compared to that in Fe/FeO.

We demonstrate that FeRh layers can be implemented to the epitaxial Fe/Au/FeRh spin valve structures grown on MgO(001). Owing to the AFM-FM phase transition in the FeRh film, the magnetic structure of our Fe/Au/FeRh system can be temperature controlled. The indirect exchange coupling between Fe and FeRh films mediated by the Au spacer enables to control the relative orientation of the Fe and FeRh magnetizations by the Au spacer thickness between ferromagnetic and non-collinear with nearly orthogonal magnetizations. Moreover, the evolution of magnetic structure of the Fe/Au/FeRh system along with the AFM-FM transition is accompanied by the reversible in-plane rotation of the top Fe-layer magnetization.We demonstrate that FeRh layers can be implemented to the epitaxial Fe/Au/FeRh spin valve structures grown on MgO(001). Owing to the AFM-FM phase transition in the FeRh film, the magnetic structure of our Fe/Au/FeRh system can be temperature controlled. The indirect exchange coupling between Fe and FeRh films mediated by the Au spacer enables to control the relative orientation of the Fe and FeRh magnetizations by the Au spacer thickness between ferromagnetic and non-collinear with nearly orthogonal magnetizations. Moreover, the evolution of magnetic structure of the Fe/Au/FeRh system along with the AFM-FM transition is accompanied by the reversible in-plane rotation of the top Fe-layer magnetization.

The structural and magnetic properties of ultrathin FeO(111) films on Pt(111) with thicknesses from 1 to 16 monolayers (ML) were studied using the nuclear inelastic scattering (NIS) of synchrotron radiation. Distinct evolution of vibrational characteristics with thickness that is revealed in the phonon density of states (PDOS) witnesses a textbook transition from 2D to 3D lattice dynamics. For the thinnest films of 1 and 2 ML, the low energy part of the PDOS followed a linear dependence in energy that is characteristic for 2-dimensional systems. This dependence gradually transforms with thickness to the bulk ~E-square relation. Density functional theory phonon calculations perfectly reproduced the measured 1 ML PDOS within a simple model of a pseudomorphic FeO/Pt(111) interface. The calculations show that the 2D PDOS character is due to a weak coupling of the FeO film to the Pt(111) substrate. The evolution of the vibrational properties with an increasing thickness is closely related to a transient long range magnetic order and stabilization of an unusual structural phase.