Direct observation of magnetic phase coexistence and magnetization reversal in a Gd0.67_{0.67}Ca0.33_{0.33}MnO3_{3} thin film

We have investigated the ferrimagnetic domain structure in a Gd$_{0.67}$Ca$_{0.33}$MnO$_{3}$ thin film using magnetic force microscopy. We observe clear signs of phase separation, with magnetic islands embedded in a non-magnetic matrix. We also directly visualize the reversal of magnetization of ferrimagnetic domains as a function of temperature and attribute it to a change in the balance of magnetization of anti-aligned Mn and Gd sublattices.Comment: 4 pages, 3 figure

Performance and characterization of a MEMS-based device for alignment and manipulation of x-ray nanofocusing optics

X-ray microscopy is a powerful, non-invasive tool used for nanometer-scale resolution imaging, and it is widely applied in various areas of science and technology. To push the spatial resolution of x-ray microscopy studies in the hard x-ray regime below 10 nm, Multilayer Laue Lenses (MLL) can be used as nanofocusing elements. To ensure distortion-free x-ray imaging, high-stability microscopy systems are required. MEMS-based manipulators are a promising route to achieve high stability when used for alignment and manipulation of nanofocusing optics. In this work, we present a tip-tilt MEMS-based device suitable for MLL alignment. We fully characterize the device and demonstrate better-than 10 millidegree angular positioning resolution when utilizing capacitive displacement sensors, and better-than 0.8 millidegree resolution when using laser interferometry

Fly-Scan Ptychography

We report an experimental ptychography measurement performed in fly-scan mode. With a visible-light laser source, we demonstrate a 5-fold reduction of data acquisition time. By including multiple mutually incoherent modes into the incident illumination, high quality images were successfully reconstructed from blurry diffraction patterns. This approach significantly increases the throughput of ptychography, especially for three-dimensional applications and the visualization of dynamic systems

Metrology of a Focusing Capillary Using Optical Ptychography

The focusing property of an ellipsoidal monocapillary has been characterized using the ptychography method with a 405 nm laser beam. The recovered wavefront gives a 12.5×10.4μm2 focus. The reconstructed phase profile of the focused beam can be used to estimate the height error of the capillary surface. The obtained height error shows a Gaussian distribution with a standard deviation of 1.3 μm. This approach can be used as a quantitative tool for evaluating the inner functional surfaces of reflective optics, complementary to conventional metrology methods

X-ray Assisted Scanning Tunneling Microscopy and Its Applications for Materials Science: The First Results on Cu Doped ZrTe3

Synchrotron X-ray Scanning Tunneling Microscopy (SX-STM) is a novel imaging technique capable of providing real space chemically specific mapping with a potential of reaching atomic resolution. Determination of chemical composition along with ultra-high resolution imaging by SX-STM can be realized through excitation of core electrons by incident X-rays when their energy is tuned to an absorption edge of a particular atom during raster scanning, as is done in the conventional STM experiments. In this work, we provide a brief summary and the current status of SX-STM and discuss its applications for material science. In particular, we discuss instrumentation challenges associated with the SX-STM technique and present early experiments on Cu doped ZrTe3 single crystals

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Propagation of the wavefield along the optical axis when there is no misalignment. The two focal planes can be seen overlap with each other

Fabrication and Characterization of CNT-Based Smart Tips for Synchrotron Assisted STM

Determination of chemical composition along with imaging at the atomic level provides critical information towards fundamental understanding of the surface of materials and, hence, yields the capability to design new materials by tailoring their ultimate functionalities. Synchrotron X-ray assisted scanning tunneling microscopy (SX-STM) is a promising new technique to achieve real space chemically specific atomic mapping. Chemical sensitivity of SX-STM relies on excitation of core electrons by incident X-rays when their energy is tuned to an absorption edge of a particular element. However, along with core-level electrons, photoelectrons are also excited, which yield additional current and interfere with the tunneling current. To reduce the background photoelectron current and to improve ultimate resolution of SX-STM, we have developed and fabricated multiwalled carbon nanotubes (MWCNT) based “smart tips” using plasma enhanced chemical vapor deposition and focused ion beam milling. The newly developed CNT-based smart tips, characterized step by step by scanning electron microscopy (SEM) during the fabrication process, demonstrate good performance and provide opportunity for realizing atomic chemical mapping