Prof. Dr. Jakub ČÍŽEKH-Index: 40
Charles University, Prague, Czech Republic, EU
Positions: Leader of the Positron Annihilation Group at the Department of Low Temperature Physics, Faculty of Mathematics and Physics, Charles University, the Czech Republic.
Specialization: Positron Annihilation Spectroscopy (PAS), Lattice defects in solids.
At the NANOCON´26 Jakub Čížek will open the Session E – Advanced Methods of Preparation and Characterization of Nanomaterials by his invited talk “Positron annihilation for characterization of defects on the atomic scale”.
Personal Background and Education:
Jakub Čížek holds a professor degree in Condensed Matter Physics (2018) and a Ph.D. in General Physics (2001) from the Faculty of Mathematics and Physics at Charles University (MFF UK) in the Czech Republic. He also earned a Master’s degree (1996) in Mathematics and Physics Teaching from MFF UK. His academic focus is on condensed matter physics, particularly in the study of lattice defects and their impact on the physical properties of solids.
He has completed several research internships, including an Alexander von Humboldt Fellowship at the Institute für Materialphysik at Georg-August-Universität Göttingen, under the supervision of Prof. Reiner Kirchheim.
His achievements include receiving the Bolzano Prize in 2001 and the Junior Scientist Award from the Learned Society of the Czech Republic in 2007.
Research interests:
Jakub Čížek and his research group concentrate on positron annihilation spectroscopy (PAS), a technique that allows for the characterization of defects at the atomic scale. PAS is highly sensitive to open volume defects and can determine both the type of defects and their concentrations in solids. The local chemical environment of defects can be characterized using coincidence Doppler broadening of annihilation radiation. By combining PAS experimental studies with first-principles theoretical calculations of positron annihilation parameters, the specific atomic arrangements of defects can be determined.
The main research topics of the group include: vacancies and vacancy complexes with impurities in semiconductors; hydrogen trapping at defects; hydrogen-induced defects; high-entropy alloys; microstructure and thermal stability of ultra-fine-grained materials created by severe plastic deformation; phase transitions and precipitation effects in Al, Ti and Mg alloys; radiation damage in solids; and characterization of free volumes in polymers.
The group of Jakub Čížek is also involved in developing PAS methodology. This includes development of high-resolution positron-lifetime spectrometers for precise measurement of positron lifetimes and extremely low background spectrometers for coincidence Doppler broadening of annihilation radiation.
In collaboration with his colleagues, he constructed a high-resolution positron lifetime spectrometer that achieves the best time resolution in the world. He also developed the first fully digital spectrometer for coincidence Doppler broadening spectroscopy, which offers superior energy resolution and clarity in the spectrum. Furthermore, he established a variable energy slow positron beam and a setup for in-situ positron annihilation measurements of hydrogen-loaded samples.
Summary of publication activity:
Author/co-author of 390 papers in international peer-reviewed journals; The number of total citations > 6.850 and H-index: 40 (Google Scholar, February, 2026); ORCID ID 
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