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Advanced UV and X-ray Probes

The CFN operates multiple end-stations at the National Synchrotron Light Source II (NSLS-II) for nanomaterials characterization. An ambient pressure x-ray photoelectron spectroscopy (AP-XPS) station enables quantitative surface chemical analysis at gas pressures up to about 1 Torr. An aberration-corrected low-energy electron /photoemission electron microscope (AC-LEEM/XPEEM) allows high-resolution spectro-microscopy of surfaces. Finally, two complementary x-ray scattering end-stations allow structural probing of complex materials at the molecular and nanoscale.

Advanced UV and X-ray Probes

Capabilities / Major Equipment

Small-angle and Wide-angle X-ray Scattering

The CFN is a partner user on two x-ray scattering beamlines at NSLS-II, through which the CFN will provide advanced structural probes, of molecular and nanoscale order, to the nanoscience user community. These beamlines provide complementary capabilities to explore complex parameter spaces (CMS beamline) and to perform frontier studies of nanomaterials (SMI beamline). The beamlines enable simultaneous small-angle and wide-angle (SAXS/WAXS) scattering experiments, including in grazing-incidence (GISAXS/GIWAXS) measurements of thin films. Capabilities for microbeams, time-resolved measurements, and resonant scattering are also available.

Aberration corrected low-energy electron / photoemission electron microscope (AC-XPEEM/LEEM) for high resolution spectro-microscopy of surfaces. The sample can be illuminated with an electron beam or focused monochromatic soft X-ray radiation with tunable photon energy (15-1500eV) and a beam diameter of 40 µm. Modes of operation include mirror electron microscopy (MEM), bright-field and dark-field LEEM, selected area low-energy electron diffraction (µ-LEED), selected-area angle- resolved photoelectron spectroscopy (µ-ARPES), X-ray photoelectron spectroscopy (XPS), and XPEEM for spatially resolved elemental imaging. The spatial resolution in the LEEM mode is better than 3 nm, better than 10 nm in the XPEEM mode, with an energy resolution of about 0.2 eV. The µ-ARPES, µ-XPS and µ-LEED measurements can be done in an area as small as 800 nm. The sample holder allows heating by electron bombardment or cooling with LN2, covering a sample temperature range from 200K to 1800K.

Ambient Pressure Photoelectron Spectroscopy (AP-PES) 

Contact: J. Anibal Boscoboinik

The AP-PES endstation allows for surface chemical analysis via core-level photoelectron spectroscopy (including XPS and XAS) at gas pressures up to ~ 3 Torr and sample temperatures up to 500 °C.  Applications include in-operando studies of surface chemistry, catalysis, and energy storage processes.  The endstation is located at the CSX-2 beamline of the National Synchrotron Light Source II (NSLS-II).  The AP-PES endstation is expected to start operations by the fall of 2015.  The photon energy range of the beamline is from 250 eV to 2 keV, covering the O 1s, N 1s and C 1s core levels as well as many transition metal core levels.  Differential pumping allows for gas pressures in the Torr range at the sample while maintaining ultrahigh vacuum conditions in the analyzer.  Suitable sample types include single crystals, foils, and powders.  Future upgrades of the endstation are aimed at achieving working pressures approaching 1 Atmosphere and implementing polarization-modulation infrared reflection absorption spectroscopy in the same system.

Endstation Details

CFN SAXS/GISAXS Endstation at NSLS-II

Contact: Kevin Yager

Upcoming Project: Complex Materials Scattering (CMS) Endstation at NSLS-II

The CFN is a partner user on the Complex Materials Scattering (CMS) beamline at Brookhaven's new, world-class synchrotron: the National Synchrotron Light Source II (NSLS-II).  The CMS beamline will be dedicated to structural studies of complex materials, including nanomaterials, soft matter, and biomolecular assemblies.  The CMS beamline will provide robust x-ray scattering capabilities across a wide q-range (simultaneous SAXS/WAXS) and at hard energies (10 keV to 17 keV); enabling both transmission-mode and reflection-mode (GISAXS and GIXD) measurements of molecular-scale and nano-scale order.  The instrument will thus be ideally-suited to studies of hybrid and hierarchical materials. In the longer-term, CMS will be developing capabilities for materials discovery.  Specifically, automation and sophisticated data analysis will enable the 'intelligent exploration' of the vast parameter spaces encountered in complex, multi-component materials.  This beamline is undergoing final commissioning. The beamline is expected to be available for general user proposals starting in the summer of 2017.

Upcoming Project: Soft Matter Interfaces (SMI) Endstation at NSLS-II

The CFN is a partner user on the Soft Matter Interfaces (SMI) beamline at Brookhaven's new, world-class synchrotron: the National Synchrotron Light Source II (NSLS-II).  The SMI beamline will provide world-leading capabilities to study the structure, energetics, and assembly of soft materials, in particular focusing on the critical role of interfaces.  SMI will be a high-flux undulator-based beamline with excellent focusing and energy-tuning capabilities.  SMI will enable simultaneous probing of small-angle and wide-angle scattering (GISAXS and GIWAXS), allowing correlating between molecular and nanoscale properties.  The tunable x-ray energy range (2.1 keV to 24 keV) will enable unprecedented studies at resonant edges relevant to soft matter (P, S, K, Ca, etc.).  The micro-focusing capabilities (~2 μm spatial resolution) will enable mapping of heterogeneous materials or assemblies, including in-operado studies of energy devices.  State-of-the-art detectors will enable high-speed (millisecond) studies of processing kinetics, and material interconversions.  This beamline is currently being commissioned. The beamline is expected to be available for general user proposals in mid-2017.

Completed Project: X9 X-ray Scattering Endstation at NSLS

The CFN acted as a contributing user to the X9 beamline at the National Synchrotron Light Source (NSLS), from its inception to final operations (2009-2014).  This high-performance undulator beamline was optimized for simultaneous small-angle (SAXS) and wide-angle (WAXS) x-ray scattering experiments, including reflection-mode analysis (GISAXS and GIXD). This suite of techniques enabled probing material structure across molecular- and nano- scales. The CFN/X9 program was highly successful, allowing hundreds of scientists to perform in-depth studies of their materials, including under in-situ conditions (e.g. control of sample temperature and ambient atmosphere). The instrument was used for demanding  solution studies, including of biomolecules, nanoparticles, and nanoscale lattices. Reflection-mode measurements empowered detailed studies on a variety of nanostructured thin films, including block-copolymers, lithographic patterns, and mesoporous materials. Hybrid and hierarchical materials were also studied in detail. For instance, numerous solar-cell materials, including organic photovoltaics, CIGS, and perovskites, were measured at X9. With the shutdown of NSLS in 2014, the X9 beamline equipment, and user program, are being transitioned to the new NSLS-II scattering beamlines (CMS & SMI).

XPEEM/LEEM Spectro-Microscopy Endstation at NSLS-II

Contact: Jurek Sadowski

The Electron Spectro-Microscopy (ESM) beamline hosts an aberration-corrected low-energy electron / photoemission electron microscope (Elmitec AC-LEEM/PEEM) equipped with an electron energy analyzer and operating in ultra-high vacuum (UHV), or in partial pressures of up to 10-6 Torr. The sample is illuminated either by an electron beam or by monochromatic focused soft x-ray radiation with tunable photon energy (15-1500 eV) and a beam size of 40 microns. Modes of operation include mirror electron microscopy (MEM), bright-field and dark-field LEEM, selected area low-energy electron diffraction (µ-LEED), selected-area angle-resolved photoelectron spectroscopy (µ-ARPES), X-ray photoelectron spectroscopy (XPS), and XPEEM for spatially resolved elemental imaging. The microscope is best suited for micro- spectroscopic investigation of conductive, crystalline surfaces with few nanometers spatial resolution. The system has a capability for in-situ physical vapor deposition and/or gas dosing. The sample temperature can be controlled from 200K to 1800K. The XPEEM/LEEM Spectro-Microscopy Endstation, as a part of the comprehensive Electron Spectro- Microscopy Facility at NSLS-II, provides unique capabilities for full-field surface topographic, crystallographic, and spectroscopic analysis at the nanoscale.