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W Drube

Publications and source records attributed to W Drube.

At least 19 recordsLinked to original sources
PubMed2004

X-ray diffraction study of the ultrathin Al2O3 layer on NiAl110.

Ultrathin Al2O3 layers on alloys are used as templates for model catalysts, tunneling barriers in electronic devices, or corrosion-resistant layers. The complex atomic structure of well-ordered alumina overlayers on NiAl110 was solved by surface x-ray diffraction. The oxide layer is composed of a double layer of strongly distorted hexagonal oxygen ions that hosts aluminum ions on both octahedral and tetrahedral sites with equal probability. The alumina overlayer exhibits a domain structure that can be related to characteristic growth defects and is generated during the growth of a hexagonally ordered overlayer (Al2O3) on a body-centered cubic (110) substrate (NiAl).

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PubMed2002

Quadrupolar transitions evidenced by resonant auger spectroscopy.

From absorption spectra, the only way to bring to the fore the occurrence of quadrupolar transitions is to study their angular dependence. Resonant spectroscopies offer a new opportunity to obtain more insight into excited electronic states by studying lineshape and intensity of decay processes. We show here that resonantly excited Ti KL(2,3)L(2,3) Auger spectra of TiO2(110) carry a clear signature of quadrupolar transitions to localized e(g) and t(2g) d-like states, giving access to a direct measurement of crystal field splitting.

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PubMed2001

Backscattering X-ray standing waves in the XUV region.

It is demonstrated that Bragg reflection of XUV radiation can be used to study structural properties of crystalline materials with large unit cells. A standing-wave field is formed in a layered TiSe2 single crystal for a near-backscattering geometry (theta = 88.5 degrees). The partial electron yield is measured as a function of photon energy across the (001) Bragg reflection condition (hv approximately equal to 1033 eV) and its characteristic modulation is compared with the results derived from dynamical diffraction theory in the two-wave approximation. The data reveal a large amount of disorder along the c-axis.

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