An ultrahigh-vacuum apparatus for resonant diffraction experiments using soft x rays (hnu=300-2000 eV)

Area of Science:

• Condensed Matter Physics
• Materials Science
• X-ray Optics

Background:

• Resonant x-ray diffraction is a powerful technique for probing electronic and magnetic structures.
• Previous limitations in soft x-ray energy ranges hindered detailed studies of specific elemental edges.

Purpose of the Study:

• To develop and characterize an advanced ultrahigh-vacuum instrument for soft x-ray resonant diffraction.
• To enable high-resolution, temperature-dependent measurements in the 300-2000 eV range.

Main Methods:

• Construction of an ultrahigh-vacuum diffractometer with precise sample manipulation (x-y-z, chi, phi axes).
• Integration of a liquid helium cryostat for measurements from 30 to 300 K.
• Utilizing polarized soft x-rays at beamline BL17SU, SPring-8.

Main Results:

• Demonstrated high reproducibility (better than 0.001 degrees) for Bragg reflections.
• Successfully measured on- and off-resonance Bragg reflections in the 530-1950 eV range.
• Confirmed reliable measurement of energy-, azimuth-, and polarization-dependent x-ray diffraction.

Conclusions:

• The developed instrument reliably performs soft x-ray resonant diffraction experiments.
• The facility is suitable for studying L-edges of transition metals, M-edges of lanthanides, and Si K-edges.
• This advancement facilitates detailed investigations of material properties using soft x-rays.