Angular dependence of the magnetization reversal in exchange biased Fe/MnF2

A detailed study of exchange-biased Fe/MnF2 bilayers using magneto-optical Kerr Effect shows that the magnetization reversal occurs almost fully through domain wall nucleation and propagation for external fields parallel to the exchange bias direction. For finite angles phi between bias and external field the magnetization is aligned perpendicular to the field cooling direction for a limited field range for decreasing fields. For external fields perpendicular to the bias direction the magnetization aligns with the field cooling direction for descending and ascending fields before fully reversing. The field range for which the magnetization is close to perpendicular to the external field can be estimated using a simple effective field model.Comment: 14 pages, 3 figures, to appear in AP

Control of the Magnetic and Magnetotransport Properties of La0.67Sr0.33MnO3 Thin Films Through Epitaxial Strain

The influence of epitaxial strain, in the form of tetragonal distortions, on the magnetic and magnetotransport properties of La{sub 0.67}Sr{sub 0.33}MnO{sub 3} thin films was studied. The tetragonal distortion (c/a ratio) was modulated through the choice of the substrate, ranging from c/a=1.007 on (001)-oriented (LaAlO{sub 3}){sub 0.3}(Sr{sub 2}AlTaO{sub 6}){sub 0.7} substrates to 0.952 on (110)-oriented GdScO{sub 3} substrates. In agreement with previous theoretical predictions, these large values of tensile strain cause the Curie temperature and the saturation magnetization to decrease, alter the temperature dependence of the resistivity and magnetoresistance, and increase the resistivity several orders of magnitude

Anisotropic x ray magnetic linear dichroism - Its importance for the analysis of soft x ray spectra of magnetic oxides

Using spectroscopic information for x ray magnetometry and magnetic microscopy requires detailed theoretical understanding of spectral shape and magnitude of dichroism signals. We have shown unambiguously that--contrary to common belief--spectral shape and magnitude of x ray magnetic linear dichroism (XMLD) are not only determined by the relative orientation of magnetic moments and x ray polarization, but also their orientations relative to the crystallographic axes must be taken into account for accurate interpretation of XMLD data

X-ray absorption study of the electronic structure of Mn-doped amorphous Si

The electronic structure of Mn in amorphous Si (a-Mn{sub x}Si{sub 1?x}) is studied by X-ray absorption spectroscopy at the Mn L{sub 3,2} edges for x = 0.005-0.18. Except the x = 0.005 sample, which shows a slight signature of Mn{sup 2+} atomic multiplets associated with a local Mn moment, all samples have broad and featureless L{sub 3,2} absorption peaks, corresponding to an itinerant state for all 3d electrons. The broad X-ray absorption spectra exclude the possibility of a localized 3d moment and explain the unexpectedly quenched Mn moment in this magnetically-doped amorphous semiconductor. Such a fully delocalized d state of Mn dopant in Si has not been previously suggested

Magnetism of NiMn2O4-Fe3O4 spinel interfaces

We investigate the magnetic properties of the isostructural spinel-spinel interface of NiMn{sub 2}O{sub 4}(NMO)-Fe{sub 3}O{sub 4}. Although the magnetic transition temperature of the NMO film is preserved, both bulk and interface sensitive measurements demonstrate that the interface exhibits strong interfacial magnetic coupling up to room temperature. While NMO thin films have a ferrimagnetic transition temperature of 60 K, both NiFe{sub 2}O{sub 4} and MnFe{sub 2}O{sub 4} are ferrimagnetic at room temperature. Our experimental results suggest that these magnetic properties arise from a thin interdiffused region of (Fe,Mn,Ni){sub 3}O{sub 4} at the interface, leading to Mn and Ni magnetic properties similar to those of MnFe{sub 2}O{sub 4} and NiFe{sub 2}O{sub 4}

Magnetic structure near the Co/NiO(001) interface

We investigate the magnetic coupling at the Co/NiO interface using soft x-ray magnetic linear dichroism (XMLD) and circular dichroism taking explicitly into account the recently observed angular dependence of the XMLD with respect to the crystallographic axes. We find that the Co moments are aligned perpendicular to the NiO moments. We discuss the impact of the anisotropic XMLD on the intensity ratio of the two peaks at the Ni L{sub 2} edge, which is commonly employed to determine the spin orientation in antiferromagnets using XMLD