Singapore Synchrotron Light Source

Makes Light Work For You
  • SINS : Surface, Interface and Nanostructure Science

    Contact: Dr. Yu Xiaojiang (slsyxjnus.edu.sg)
  • SINS facility uses a bending magnetic beamline to deliver photon with an energy range from 50-1200 eV for end-station to cover the K-edges of light elements (C, N, and O) and L-edges of transition metals, and M-edges of part of rare earth metals, with user selectable linear and circular polarization for soft x-ray photon. There are two measurement chambers (main chamber and XMCD chamber) in the end-station, which are designed for X-ray photoelectron spectroscopy (XPS), angle-resolved photoemission (ARPES), X-ray absorption spectroscopy (XAS), X-ray linear dichroism (XMLD) and X-ray magnetic circular dichroism (XMCD) experiments. These experiments are helpful in probing elemental compositions, electronic and magnetic states of materials, work functions and molecular orientation in the self-assembled monolayers (SAM). With these detailed information, it provides the opportunities to uncover the exotics properties regarding many fundamental questions in solid-state physics.
  • Specifications

  • Beamline type VUV and Soft X-ray beamline
    Energy range50 – 1200 eV
    Monochromator SGM, Including angle 174º
    Calculated flux (0.7 GeV, 300 mA)> ~1010 photons/s (E/ΔE=1000) @500 eV
    Resolving power (E/ΔE)> 103 (E/ΔE) @500eV, 100 µm slit widths
    Spot size at sample (H X V)1.5 x 0.2 mm2 (main chamber)
    4 x 3 mm2 (XMCD chamber) (FWHM)
    Polarization DegreeLinear polarization>95%, circular polarization>80%
  • End-station

  • Main chamber
    EquipmentTechniques
    Angle-resolved photoemission with a Scienta R4000 electron analyzerAngle-resolved photoemission, X-ray photoelectron Spectroscopy, X-ray absorption spectroscopy (XAS) in TEY (Total electron yield) and AEY (Auger electron yield) modes.
    LEEDLow energy electron diffraction
    Sputtering gunAr+ bombard clean sample
    XMCD chamber
    Magnet (HTS-110)Sweep from -2 T to +2T (Present ±1.2T )
    Manipulator from SPECSX-ray absorption spectroscopy (XAS) in TEY mode, X-ray Magnetic circular dichroism (XMCD)
    Temperature control78 K-330K (LN2), 10K-330K (LHe)
    Vacuum pressures
    Main chamber (mbar)2x10-10
    XMCD chamber (mbar)5x10-10
  • Sample preparation

  • An Omicron sample plate used to hold the samples, if sample size is 8x2.5mm2, up to 4 samples can be mounted.

    Samples should be UHV compatible solid materials, may be bulk or thin film, powder material should be compressed into thin flake.

    Maximum sample size is 10x10 mm2; thickness usually is less than 3 mm. However, to use less size samples to mount more samples on a single plate, will reduce greatly the time to exchange the samples from load-lock chamber to both measurement chambers.

    For XMCD measurement, due to big beam spot size, please use larger sample (8x5 mm2) and at most two samples on single plate.

    For thin films growth on insulator substrate, a carbon tape is used to electrically short-cut sample surface with plate, prevent of sample charging.

  • Exemplified results

  • XAS and XMCD measurements at Fe L-edges for multilayers with giant perpendicular magnetic anisotropy (PMA)[ Lourembam, J. , Yu, X. J., et al. (2020) Phys. Rev. Appl., 14, 054022–12.]

  • Work function, Surface coverage (ΨSAM), thickness of SAM (dSAM) of self-assembled monolayers (SAMs) determined by angle-dependent X-ray photoelectron spectroscopy [ X. Chen, B. Kretz, F. Adoah, C. Nickle, X. Chi, X. Yu, E. del Barco, D. Thompson, D.A. Egger, and C.A. Nijhuis, “A single atom change turns insulating saturated wires into molecular conductors,” Nat. Commun. 12, 3432 (2021).] .