Hysteretic Spin-Density-Wave Ordering in Confined Geometries

Abstract

We have measured the antiferromagnetic spin-density-wave (SDW) order in Cr/Cr(97.5)Mn2.5(001) superlattices. The Mn doping creates a high Néel temperature layer that confines the incommensurate SDW order within the Cr layers. With temperature cycling we observe a transition from commensurate to incommensurate SDW order and discrete changes in the SDW period. We find that these transitions show significant hysteresis (up to 75 K) when the number of SDW nodes within the Cr layer changes by an odd number, while there is no hysteresis for changes of an even number of nodes. This results from the competition between maintaining the spin structure at the interfaces and introducing a spin slip at the nodes of the Cr SDW.

Soft x-ray resonant magneto-optical Kerr effect as a depth-sensitive probe of magnetic heterogeneity: Its application to resolve helical spin structures using linear p polarization

“…These MO properties are very useful to determine the depth-varying spin structures by fitting the measured specular I K versus to those calculated from the various model configurations, as used in x-ray/neutron scattering experiments and analysis of the structural refinements. [19][20][21] The specular Kerr intensity reflected from a magnetized film in the vicinity of the resonance thresholds is a kind of an x-ray resonant magnetic scattering. As reported in Ref.…”

“…[13][14][15][16][17][18] Specifically, the K and K spectra, as a function of the grazing angle of incidence for different photon energies h s near the resonance regions, provide invaluable information on magnetic heterostrutures, such as depth-varying spin directions, so that these spectra are very informative to determine the depth-dependent spin structure inherently present in the magnetic multilayer films that consist of several ultrathin layers of different elements. While neutron scattering, 19 and resonant specular 20 and off-specular 21 reflectivity have been a tool to study the magnetic heterogeneity in the films imposed by chemical inhomogeneity.…”

Influence of growth morphology on the Néel temperature of CrRu thin films and heterostructures

“…6. This may be ascribed [3,[14][15][16]] to proximity magnetism. The Ru doping creates a high T N Cr 0.9965 Ru 0.0035 layer of thickness 10 nm that orders in a CSDW phase below T N E420 K (Fig.…”

“…The ISDW period varies from 78Å at T N to 60Å at 10 K [2,3]. Thin films and heterostructures of Cr and Cr alloys show fascinating properties, not observed in the bulk [3,4], including the mediating role of Cr thin films in exchange coupled superlattices and in giant magnetoresistive (GMR) materials [2].…”

Tunnel-mediated coupling between antiferromagnetic thin films

“…The discovery of giant magnetoresistance in Fe/Cr superlattices [5] triggered an intense research effort on the magnetic properties of Cr thin films [6,7] and multilayers [8][9][10][11][12]. In all these examples, the magnetism remains purely itinerant since all layers are metallic.…”