Speaker
Description
Research on highly correlated systems is a key trend in physics. The RE₃Ni₅Al₁₉ series has been the subject of intensive research on the physical properties of actinides (RE = U and Th) and lanthanides (RE = Sm and Yb). It has been shown that U₃Ni₅Al₁₉ is a heavy-fermion antiferromagnet with TN = 23 K and exhibits non-Fermi liquid behavior below 5 K under ambient pressure [1]. The unusual and interesting behavior of known RE₃Ni₅Al₁₉ compounds has recently inspired research on other RE atoms in this structure, which may lead to the discovery of new materials with unusual properties. Further research may contribute to a better understanding of the magnetic properties and their complexity in this series of compounds.
We present temperature-dependent spectroscopic studies of the electronic structure and magnetic behavior of monocrystalline intermetallic compounds RE₃Ni₅Al₁₉ synthesized via the Al self-flux method. These compounds exhibit complex magnetic behavior with multiple phase transitions (three for both Gd₃Ni₅Al₁₉ and Tb₃Ni₅Al₁₉), suggesting strong interplay between electronic structure and magnetism [2]. Using high-resolution X-ray photoelectron spectroscopy (XPS) and resonant photoemission spectroscopy (ResPES) at photon energies corresponding to the M-edges of RE and the L-edge of Ni, we investigate the temperature-induced changes in the partial density of electronic states in the valence band. Measurements are performed both at room temperature and in the low-temperature regime, above and below the observed phase transition points (25 K and 21 K for Gd₃Ni₅Al₁₉; 32 K, 29 K, and 20 K for Tb₃Ni₅Al₁₉). The goal is to distinguish the individual electronic contributions of Ni and rare-earth atoms to the valence band near the Fermi level, and to correlate these with the magnetic ordering processes occurring at different temperatures.
Acknowledgements: The research activities co-financed by the funds granted under the Research Excellence Initiative of the University of Silesia in Katowice
References
[1] E. D. Bauer, V. A. Sidorov, S. Bobev, D. J. Mixson, J. D. Thompson, J. L. Sarrao, M. F. Hundley, Phys. Rev. B 2005, 71, 014419.
[2] Z. Ryżyńska, M. Marshall, W. Xie, T. Klimczuk, M. J. Winiarski, Cryst. Res. Technol. 2023, 58, 2200170.
