X-Ray microscopy: HZB-TXM is back in operation
Comparison of the same specimen at the old Beamline (left) and the new HZB-XM-Beamline (right). © HZB
The X-ray microscope (HZB-TXM) is back in operation. The TXM offers significantly better quality images compared to the former X-ray microscopy station.
It is located at the brand-new U41-L06-PGM1-XM Beamline, which was designed to extend the available photon energy range to the tender X-ray regime (2 keV -2,5 keV). This will allow accessing the silicon, phosphor and sulphur K-edges to study crucial processes in cell membranes and catalysts.
Pictures of identical test objects demonstrate the improved performance of the new TXM. The X-ray microscopy is much in demand by users worldwide and the new TXM is already overbooked for the beamtime allocation period 2017-II. First user experiments have been already conducted.
Spintronics at BESSY II: Domain walls in magnetic nanowires
Magnetic domains walls are known to be a source of electrical resistance due to the difficulty for transport electron spins to follow their magnetic texture. This phenomenon holds potential for utilization in spintronic devices, where the electrical resistance can vary based on the presence or absence of a domain wall. A particularly intriguing class of materials are half metals such as La2/3Sr1/3MnO3 (LSMO) which present full spin polarization, allowing their exploitation in spintronic devices. Still the resistance of a single domain wall in half metals remained unknown. Now a team from Spain, France and Germany has generated a single domain wall on a LSMO nanowire and measured resistance changes 20 times larger than for a normal ferromagnet such as Cobalt.
Graphene on titanium carbide triggers a novel phase transition
Researchers have discovered a Lifshitz-transition in TiC, driven by a graphene overlayer, at the photon source BESSY II. Their study sheds light on the exciting potential of 2D materials such as graphene and the effects they can have on neighboring materials through proximity interactions.
How much cadmium is contained in cocoa beans?
Cocoa beans can absorb toxic heavy metals such as cadmium from the soil. Some cultivation areas, especially in South America, are polluted with these heavy metals, in some cases considerably. In combining different X-ray fluorescence techniques, a team at BESSY II has now been able to non-invasively measure for the first time where cadmium accumulates exactly in cocoa beans: Mainly in the shell. Further investigations show that the processing of the cocoa beans can have a great influence on the concentration of heavy metals.