X-ray interferometry of surfaces with Fresnel mirrors.

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.

Magnetization profile of ultrathin FePd films.

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.

Hysteresis effect in FePd magnetic stripes studied by coherent soft X-ray resonant magnetic scattering.

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.

Direct 3D imaging of Al70.4Pd21Mn8.6 quasicrystal local atomic structure by X-ray holography.

Inverse x-ray fluorescence holography was used to explore the local atomic order of a nearly perfect quasicrystal with composition Al70. 4Pd21Mn8.6.