RESUMEN
Inverse x-ray fluorescence holography was used to explore the local atomic order of a nearly perfect quasicrystal with composition Al70. 4Pd21Mn8.6. We have demonstrated the possibility of direct 3D imaging of the atomic decoration in a quasicrystal. We have obtained the average 3D environment of selected coordination shells around the Mn atoms. These results open the way to obtaining further and more complete information about the various coordination shells in complex materials by measuring multiple energy x-ray holograms at different sites.
RESUMEN
With a small double-mirror setup, we used grazing-x-ray interferometry to study nanometric steps. These one-dimensional steps were microfabricated upon the surface of one of the two mirrors; the other mirror provided the reference wave. Two geometries were studied. In the longitudinal case in which the x rays are parallel to the step edges, it is straightforward to determine the step size. In the transverse case, one deals with Fourier holography, and a reconstruction process for a phase object had been demonstrated for the case of a single step.
RESUMEN
Using two small flat mirrors under grazing incidence, we have produced interference patterns from partially coherent x-ray beams at the European Synchrotron Radiation Facility. By piezoelectrically orienting one mirror around the horizontal plane, both the vertical and horizontal transverse coherence distances of the radiation have been measured. The experimental setup can be used to characterize the coherence properties along x-ray synchrotron beamlines.
RESUMEN
An FePd thin film sample, showing magnetic stripe domains as imaged by magnetic force microscopy, has been measured by soft X-ray resonant magnetic scattering in reflection geometry. Illumination with coherent radiation, produced by inserting a 20 microm pinhole in front of the sample, leads to a magnetic speckle pattern in the scattered intensity that gives access to the domain morphology. Application of an in-plane magnetic field for a few seconds gives a strong change in the observed intensity fluctuations, which indicates a large degree of variation between the two patterns taken before and after field exposure. From the speckle pattern we calculate a degree of coherence of beta = 0.5 for the incident beam.
Asunto(s)
Cristalización/métodos , Hierro/química , Magnetismo , Nanotecnología/métodos , Paladio/química , Difracción de Rayos X/métodos , Anisotropía , Hierro/efectos de la radiación , Ensayo de Materiales , Dinámicas no Lineales , Paladio/efectos de la radiaciónRESUMEN
The method of circular dichroism in X-ray resonant magnetic scattering is presented which allows a straightforward determination of the magnetization profile of magnetic patterns in ultrathin films. Application to single crystalline FePd layers shows unambiguously the presence of magnetic flux closure domains whose thickness can constitute a significant fraction ( approximately 25%) of the total film.
RESUMEN
The magnetization profile of magnetically ordered patterns in ultrathin films was determined by circular dichroism in x-ray resonant magnetic scattering (CDXRMS). When this technique was applied to single crystalline iron palladium alloy layers, magnetic flux closure domains were found whose thickness can constitute a large fraction ( approximately 25 percent) of the total film.