Magnetic x-ray microscopy on high-Tc superconductors
Flux density distrinbuition in a YBCO cristalline bulk sample.
Cryostat based on liquid nitrogen inside the x-ray microscope.
To visualize the local critical current density in superconductors with high spatial resolution, the wavelength of magneto-optical imaging is transferred into the soft x-ray regime. The shorter wavelength combined with a novel and thin sensor layer establishes a spatial resolution of 130nm. We use amorphous, ferromagnetic CoFeB as sensor layer on top of the high-temperature superconductor YBCO. These double-layers are being examined with XMCD microscopy in the x-ray microscope MAXYMUS at the beamline UE46-PGM2 at the synchrotron BESSY II in Berlin. This x-ray microscope, part of department Schütz, was upgraded with a MMR Micro Miniature Joule-Thompson Cryostat, which delivers the measurement temperatures in the range of 75K to 580K.