Micro-focused X-ray beams produced by third generation synchrotron sources offer new perspective of studying strains and processes at nanoscale. Atomic force microscope setup combined with a micro-focused synchrotron beam allows precise positioning and nanomanipulation of nanostructures under illumination. In this paper, we report on integration of a portable commercial atomic force microscope setup into a hard X-ray synchrotron beamline. Details of design, sample alignment procedure, and performance of the setup are presented.

A strong bias asymmetry of the spin-injection efficiency through an epitaxial Fe/GaAs Schottky tunnel contact is observed. Low-temperature post-growth thermal annealing is shown to strongly affect the spin-injection efficiency. The annealing leads either to a reduction or an enhancement. The spin accumulation is addressed electrically in a lateral spin-valve geometry using a non-local spin-valve setup at liquid helium temperatures. A spin-injection efficiency of up to 5.5% is estimated from experimental results. The electrical properties of the Schottky tunnel diode do not reflect the bias asymmetry and the changes in the spin-injection efficiency during annealing. Formation of spin-polarized interface states (IS) close to the Fermi-level is a possible explanation. The IS will not only radically affect the spin-injection but also the spin-detection process.

Phase change materials are attractive materials for non-volatile memories because of their ability to switch reversibly between an amorphous and a crystal phase. The volume change upon crystallization induces mechanical stress that needs to be understood and controlled. In this work, we monitor stress evolution during crystallization in thin GeTe films capped with SiOx, using optical curvature measurements. A 150 MPa tensile stress buildup is measured when the 100 nm thick film crystallizes. Stress evolution is a result of viscosity increase with time and a tentative model is proposed that renders qualitatively the observed features.

MgO tunneling barriers are extensively studied as a spin filtering and diffusion barrier for deposition of ferromagnetic layers on GaAs (001) surfaces. The relatively large lattice mismatch of the MgO and GaAs substrate and probable formation of interface states at the metal layer side require a careful barrier design. We present a study of deposition, microstructure, and strain relaxation in MgO barriers deposited on GaAs. The dependence of morphology of MgO layers on their thickness was characterized using a combination of X-Ray Reflectivity and High Resolution Transmission Electron Microscopy. The stress at the MgO/GaAs interface was observed to be released through the formation of misfit dislocations and partially by the formation of mis-oriented domains. The deposited MgO and Fe layers were found to be highly textured irrespective of the thickness of MgO layers. Energy dispersive X-ray microanalysis was used to observe intermixing at the interface of Fe and MgO layers.