Time-resolved soft X-ray microscopy of magnetic nanostructures at the P04 beamline at PETRA III

摘要

We present first time-resolved measurements of a new mobile full-field transmission microscope [1] obtained at the soft X-ray beamline P04 at the high brilliance synchrotron radiation source PETRA III.A nanostructured magnetic permalloy (Ni_(80)Fe_(20)) sample can be excited by the magnetic field of a 400 ps full width at half maximum (FWHM) long electric current pulse in a coplanar waveguide.The full-field soft X-ray microscope successively probes the time evolution of the sample magnetization via X-ray magnetic circular dichroism (XMCD) [2] spectromicroscopy in a pump-probe scheme by varying the delay between pump and probe pulses electronically.Static and transient magnetic fields of a permanent magnet and a coil are available in the sample plane to reset the system and to provide external offset fields.The microscope generates a flat-top illumination field of 20 μm diameter by using a grating condenser [3] and the sample plane is directly imaged by a micro zone plate with 60 nm resolution onto a 2D gateable X-ray detector to select the particular bunch in the storage ring that contains the dynamic information.The setup is built into a mobile endstation vacuum system with in-house developed three-axis piezo motorized stages for high accuracy positioning of all microscopy-components inside the chambers.