Abstract: With the advent of high-quality X-ray optics, several techniques have been proposed to exploit imaging under Bragg conditions at synchrotron sources. Within the framework of the European Synchrotron upgrade, a new dedicated instrument has been implemented on beamline ID01. Since April 2017, this instrument has been fully operational and has supplied users with full-field diffraction X-ray microscopy (FFDXM) imaging adapted to various sample environments. Compared with more established scanning diffraction techniques, FFDXM offers fast, spatially resolved images on a large sample area without mechanical motions, perfectly suited for in situ and operando experiments.
The concept of FFDXM will be first demonstrated. A set of objective lens is placed downstream of the sample to make a dark field image of the diffracted beam. At 6.5 meters away, the illuminated sample area (field of view : 200×200 μm2) is magnified and spatially resolved on a sCMOS camera with a resolution of 100 nm. Essentially an X-ray strain microscope, the FFDXM is capable of probing lattice tilt, strain, and grain orientation at surfaces and buried interfaces or inside functioning devices, which is often unreachable for electron microscopy techniques.
Results of several user and in-house experiments will be given next to illustrate the principle of diffraction topography (strained STO), mosaicity (InGaN nano-pyramids), and strain (buried gas cavities in implanted silicon wafers) mapping using FFDXM. Typical image acquisition time is around 1 sec; a complete set of measurement takes just a few minutes.
Based on these measurement techniques, more complex experiments were conducted. The final part of the talk will cover preliminary results and outlook from the most recent developments of the microscope, including in situ heating and cryogenic cooling, operando chemistry, sub-nanosecond time-resolved and composition-sensitive imaging.