Elucidation of the Co state with strong charge-transfer effects in charged LiCoO by resonant soft X-ray emission spectroscopy at the Co L edge.

To understand the electronic-structure change of LiCoO, a widely used cathode material in Li-ion batteries, during charge-discharge, we performed soft X-ray absorption spectroscopy (XAS) and resonant soft X-ray emission spectroscopy (RXES) of the Co L edge in combination with charge-transfer multiplet calculations. The RXES profile significantly changed for the charged state at 4.2 V Li/Li, corresponding to the oxidation reaction from a Co low-spin state for the initial state, while the XAS profile exhibited small changes.

Electronic structures of blue copper centers of amicyanin and azurin in the solution state.

X-ray absorption near edge structure (XANES) spectra of blue copper proteins, amicyanin and azurin, in the solution state were measured in the copper L-edge energy region. The absorption peak energies were quite similar for both proteins, while the main edge region for azurin was broader than that for amicyanin, owing to more pronounced shoulder spectral features in the former. calculations at the whole protein level qualitatively reproduced the experimental spectra well.

Reevaluation of the Suitability of Xe Nuclear Magnetic Resonance Spectroscopy for Pore Size Determination in Porous Carbon Materials.

Xenon isotope nuclear magnetic resonance (Xe-NMR) spectroscopy has been widely used to evaluate the pore structure of materials. However, determining how to apply this technique to investigate porous carbon materials is sometimes challenging, partly due to the structural disorder and heterogeneity of the surface properties of these materials, and partly due to the lack of reliable methods for controlling and assessing the density of adsorbed Xe. In this study, we designed and constructed a temperature- and pressure-controllable Xe-NMR system to evaluate the interaction between activated carbon (AC) and adsorbed Xe molecules.

The role of carboxylate ligand orbitals in the breathing dynamics of a metal-organic framework by resonant X-ray emission spectroscopy.

Metal-organic frameworks (MOFs) exhibit structural flexibility induced by temperature and guest adsorption, as demonstrated in the structural breathing transition in certain MOFs between narrow-pore and large-pore phases. Soft modes were suggested to entropically drive such pore breathing through enhanced vibrational dynamics at high temperatures. In this work, oxygen K-edge resonant X-ray emission spectroscopy of the MIL-53(Al) MOF was performed to selectively probe the electronic perturbation accompanying pore breathing dynamics at the ligand carboxylate site for metal-ligand interaction.

Angle-resolved X-ray emission spectroscopy facility realized by an innovative spectrometer rotation mechanism at SPring-8 BL07LSU.

The X-ray emission spectrometer at SPring-8 BL07LSU has recently been upgraded with advanced modifications that enable the rotation of the spectrometer with respect to the scattering angle. This major upgrade allows the scattering angle to be flexibly changed within the range of 45-135°, which considerably simplifies the measurement of angle-resolved X-ray emission spectroscopy. To accomplish the rotation system, a sophisticated sample chamber and a highly precise spectrometer rotation mechanism have been developed.