Tohoku University develops system to realize broadband X-ray ptychography — Using NanoTerasu to visualize material structures with high precision

X-ray ptychography, which enables high-precision visualization of material structures at the nanometer scale, has attracted attention as a non-destructive, high-resolution observation technique. However, until now, there was no system that could perform measurements from the tender X-ray range (energy region around 2-5 keV) to the hard X-ray range (5 keV and above) using the same equipment.

A research team led by Graduate Student Yuhei Sasaki from the School of Engineering, with Associate Professor Nozomu Ishiguro and Professor Yukio Takahashi from the International Center for Synchrotron Radiation Innovation Smart (SRIS) at Tohoku University, successfully developed a high-resolution X-ray ptychography system capable of operating across a broad energy range from tender to hard X-rays by utilizing a beamline at NanoTerasu, a 3 GeV synchrotron radiation facility. Their results were published online in IUCrJ.

The system combines NanoTerasu's high-brilliance and high-coherence X-rays with a highly efficient total reflection focusing optical system free from chromatic and coma aberrations, along with the CITIUS high-speed integrating X-ray image detector capable of handling tender to hard X-rays. This combination enables measurements to be conducted while continuously sweeping the energy range without changing the focused beam position. As a result, the team achieved X-ray ptychography measurements spanning both tender and hard X-ray regions for the first time, which had been difficult with conventional systems. When the system was installed on the beamline and test samples were measured, resolutions of 38.7 nanometers at 2.5 keV, 13.4 nanometers at 5 keV, and 16.1 nanometers at 7.5 keV were obtained.

Furthermore, the team successfully reconstructed nanometer-scale images and acquired X-ray absorption spectra at the tens-of-nanometers scale near the K absorption edges of calcium and sulfur in calcium sulfate samples.

This system provides a powerful technological foundation for simultaneously visualizing local structures and chemical states in multi-element materials across three-dimensional space plus energy. Looking ahead, the team aims to develop X-ray spectroptychography with even higher resolution and stability for industrial materials such as battery materials, metal alloys, and catalysts. The system is expected to be utilized as an analytical method contributing to the digital transformation of materials and green transformation.

Journal Information
Publication: IUCrJ
Title: Broadband high-resolution X-ray ptychography system spanning tender to hard X-ray regimes
DOI: 10.1107/S2052252525009236