arXiv subjects

Hiroaki Kimura

Publications and source records attributed to Hiroaki Kimura.

3 recordsLinked to original sources

arXiv2026

Photoelectron angular distribution as a linear polarization analyzer for soft and tender X-rays

Although the polarization of soft and tender X-rays is widely used to investigate the diverse physical properties of materials, experimental methods to determine the polarization of tender X-rays (1.5-3.0 keV) remain limited. To address this issue, we propose a method based on the photoelectron angular distribution to detect the polarization of X-rays in this energy range. The angular distribution of photoelectrons emitted from carbon targets was measured using linearly polarized 0.2 to 3.0 keV synchrotron radiation. The photoelectron intensity depends on the angle between the photon's electric field vector and the direction at which the photoelectron is emitted from the target. This result indicates that the photoelectron angular distribution can be used to reliably determine the linear polarization of soft and tender X-rays over a wide range of energy.

cond-mat.mtrl-sci↗

arXiv2008

Metallic Pattern Fabrication in Organic Mott Insulating Crystal by Local X-Ray Irradiation

We have fabricated a metallic structure in an organic Mott insulator $κ$-(BEDT-TTF)$_2$Cu[N(CN)$_2$]Cl. The periodic metallic domains of approximately 90$\times$90 $μ$m$^2$ obtained by X-ray irradiation through a molybdenum mesh mask are visualized by scanning microregion infrared reflectance spectroscopy technique. No deterioration by irradiation is found in a range of nanometer to micrometer scales. We demonstrate that the present processing method is applicable for the fabrication of molecular electronic devices.

cond-mat.str-el↗

arXiv2003

Infrared study of spin crossover Fe-picolylamine complex

Infrared (IR) absorption spectroscopy has been used to probe the evolution of microscopic vibrational states upon the temperature- and photo-induced spin crossovers in [Fe(2-picolylamine)3]Cl2EtOH (Fe-pic). To overcome the small sizes and the strong IR absorption of the crystal samples used, an IR synchrotron radiation source and an IR microscope have been used. The obtained IR spectra of Fe-pic show large changes between high-spin and low-spin states for both the temperature- and the photo- induced spin crossovers. Although the spectra in the temperature- and photo-induced high-spin states are relatively similar to each other, they show distinct differences below 750 cm-1. This demonstrates that the photo-induced high-spin state involves microscopically different characters from those of the temperature-induced high-spin state. The results are discussed in terms of local pressure and structural deformations within the picolylamine ligands, and in terms of their possible relevance to the development of macroscopic photo-induced phase in Fe-pic.

cond-mat.soft↗