Extreme conditions research using the large-volume press at the P61B endstation, PETRA III.

Penetrating, high-energy synchrotron X-rays are in strong demand, particularly for high-pressure research in physics, chemistry and geosciences, and for materials engineering research under less extreme conditions. A new high-energy wiggler beamline P61 has been constructed to meet this need at PETRA III in Hamburg, Germany. The first part of the paper offers an overview of the beamline front-end components and beam characteristics.

Progress in HAXPES performance combining full-field k-imaging with time-of-flight recording.

An alternative approach to hard-X-ray photoelectron spectroscopy (HAXPES) has been established. The instrumental key feature is an increase of the dimensionality of the recording scheme from 2D to 3D. A high-energy momentum microscope detects electrons with initial kinetic energies up to 8 keV with a k-resolution of 0.

Interface Engineering to Create a Strong Spin Filter Contact to Silicon.

Integrating epitaxial and ferromagnetic Europium Oxide (EuO) directly on silicon is a perfect route to enrich silicon nanotechnology with spin filter functionality. To date, the inherent chemical reactivity between EuO and Si has prevented a heteroepitaxial integration without significant contaminations of the interface with Eu silicides and Si oxides. We present a solution to this long-standing problem by applying two complementary passivation techniques for the reactive EuO/Si interface: (i) an in situ hydrogen-Si (001) passivation and (ii) the application of oxygen-protective Eu monolayers-without using any additional buffer layers.

Oxidation-state analysis of ceria by X-ray photoelectron spectroscopy.

Three different methods to determine the oxide-phase concentration in mixed cerium oxide by hard X-ray photoelectron spectroscopy are applied and quantitatively compared. Synchrotron-based characterization of the O 1s region was used as a benchmark to introduce a method based on the weighted superposition of the Ce 3d spectra of the pure Ce(3+) and Ce(4+) phases, which was shown to lead to reliable and highly accurate determination of the mean oxidation state in mixed cerium oxides. The results obtained reveal a linear relation between the third distinct final state (u''') satellite peak intensity of the Ce(4+) phase and the Ce(4+) concentration by proper inclusion of Ce(3+)-related plasmon satellite peaks, which contradicts previous claims of nonlinear behavior.

Bulk sensitive hard x-ray photoemission electron microscopy.

Hard x-ray photoelectron spectroscopy (HAXPES) has now matured into a well-established technique as a bulk sensitive probe of the electronic structure due to the larger escape depth of the highly energetic electrons. In order to enable HAXPES studies with high lateral resolution, we have set up a dedicated energy-filtered hard x-ray photoemission electron microscope (HAXPEEM) working with electron kinetic energies up to 10 keV. It is based on the NanoESCA design and also preserves the performance of the instrument in the low and medium energy range.