Yutaka Yoshida in conversation with Ralf Röhlsberger

A Special Gift for Research

A visiting professor from Japan brings a new microscopy technique to the Friedrich Schiller University Jena
Yutaka Yoshida in conversation with Ralf Röhlsberger
Image: Jens Meyer (University of Jena)
  • Light

Published: | By: Stephan Laudien, English translation by Gleb Chupakhin

This collaboration is special: When the Japanese Physicist Prof. Dr. Yutaka Yoshida retired, he made his ACP colleague in Jena Prof. Dr. Ralf Röhlsberger the offer to ship his modern microscopy laboratory to the Saale. Why not continue the research in Jena? Thus, the Helmholtz Institute and the Friedrich-Schilller-University Jena obtained Prof. Yoshida as a Guest Professor for two years. The microscopy laboratory from far-away Shizuoka has in the meantime begun its work at the Max-Wien-Platz in Jena.

Making material irregularities visible with specific technology

Prof. Yoshida developed Mößbauer microscopy between 2008 and 2016 at the Shizuoka Institute of Technology. This technique makes inhomogeneities in modern composite materials visible. As ACP principal scientist Prof. Röhlsberger from the Institute for Optics and Quantum Electronics explains, it is exactly the nanometer-scale irregularities in atomic properties that cause the characteristics of modern materials. “However, in many cases, for example in solar cells, these irregularities limit the efficiency and functionality of the materials”, says Prof. Yoshida. It is here that Mößbauer microscopy gets utilized. Ralf Röhlsberger says that special atomic nuclei, the so-called Mößbauer isotopes, are used as probes that are able to provide sensitivities and picture contrasts orders of magnitude better than conventional imaging techniques. These specific isotopes are named after Rudolf Mößbauer, who was honored with the Nobel Prize in 1961 for their discovery. “Thanks to this technique, we are able to observe and customize the properties of new materials, especially in micro- and nanostructures, already during production”, according to Ralf Röhlsberger. The new technique will be used for the investigation of the spatial distribution of iron atoms in silicon solar cells, the phase separation of complex materials near phase transitions, and the spatially-resolved oscillation behavior of piezoelectric membranes.

Yoshidas laboratory came as a present from Shizuoka to Jena

Ralf Röhlsberger from the Professorship for X-ray Physics has been cooperating with Prof. Yoshida since 2018. Now, since the meanwhile-69-year-old Japanese academic has retired, his microscopy laboratory in Shizuoka will be dissolved. Thus the idea was born to transfer the machines to Jena. The equipment arrived as a gift to Jena; the Helmholtz Institute only bore the transport costs.

Prof. Yoshida and his wife Itsuko feel very comfortable in Jena. Yutaka Yoshida has already worked as a young scientist for extended periods in Berlin and Vienna – he speaks excellent German. Itsuko Yoshida is a concert pianist and, as her husband says, has already enriched multiple scientific conferences with her fantastic playing. “We hope that she will fully display her artistic talents during planned scientific conferences in Jena”, says Ralf Röhlsberger.


Ralf Röhlsberger, Prof. Dr