Researchers at Ohio University have achieved a milestone in atomic imaging by X-raying individual iron and terbium atoms for the first time. This breakthrough enhances understanding of the chemical properties that govern these elements at the smallest scales, opening doors to more precise characterizations of atomic behavior and electronic structure. The findings are reported in a formal scientific article detailing the method and its implications.
To capture images of single atoms, scientists traditionally rely on specialized microscopes that scan a sample with a tiny probe. The electric current generated by the probe depends on the properties of the atoms being studied, and scientists reconstruct an image of the atom by analyzing how the current changes in response to those properties. This approach has been a cornerstone of nanoscale imaging for decades, providing rich insight into atomic arrangements and interactions.
The team pursued a new direction by designing an X-ray version of this scanning concept, called Synchrotron X-ray Scanning Tunnel Microscopy, or SX-STM. In this approach, a narrow beam of X-rays illuminates the sample and excites the atoms within. The excitation causes electrons to occupy different energy levels and orbital configurations. As a result, photons of various wavelengths are absorbed in characteristic ways, enabling researchers to distinguish not only the identity of the atom but also its chemical state. This capability marks a significant advance in chemical state mapping at the level of individual atoms, with potential to reveal subtleties in how atoms interact with their surroundings.
According to the study authors, the team successfully determined the chemical states of single atoms and compared these states across different molecular environments. The results show that terbium, a rare earth metal, tends to remain relatively isolated in the tested complexes, while iron exhibits stronger interactions with its surroundings. These observations provide new clues about how electronic structure and local bonding influence atomic behavior in complex systems, a topic of great interest for materials science and chemistry.
Beyond the atomic scale imaging, the researchers highlight a practical pathway toward energy-efficient light sources. Scientists affiliated with Penza State University developed a method to create lasers that can be tuned across wavelengths with lower energy input. This wavelength-tuning technology has broad potential applications, from spectroscopic analysis and the study of quantum systems to the fabrication of microcircuits and the detailed investigation of substances used in medicine and information transmission networks. The advancement signals a step forward in how light sources can be controlled and optimized for diverse scientific and technological tasks, potentially enabling more compact and power-saving photonic devices.