TY  - INPR
A1  - Song, Young-Joon
A1  - Schulz, Susanne
A1  - Kliemt, Kristin
A1  - Krellner, Cornelius
A1  - Valentí, Roser
T1  - Microscopic analysis of the valence transition in tetragonal EuPd2Si2
T2  - arXiv
N2  - Under temperature or pressure tuning, tetragonal EuPd2Si2 is known to undergo a valence transition from nearly divalent to nearly trivalent Eu accompanied by a volume reduction. Albeit intensive work, its microscopic origin is still being discussed. Here, we investigate the mechanism of the valence transition under volume compression by ab initio density functional theory (DFT) calculations. Our analysis of the electronic and magnetic properties of EuPd2Si2 when approaching the valence transition shows an enhanced c-f hybridization between localized Eu 4f states and itinerant conduction states (Eu 5d, Pd 4d, and Si 3p) where an electronic charge redistribution takes place. We observe that the change in the electronic structure is intimately related to the volume reduction where Eu-Pd(Si) bond lengths shorten and, for the transition to happen, we trace the delicate balance between electronic bandwidth, crystal field splitting, Coulomb repulsion, Hund's coupling and spin-orbit coupling. In a next step we compare and benchmark our DFT results to surface-sensitive photoemission data in which the mixed-valent properties of EuPd2Si2 are reflected in a simultaneous observation of divalent and trivalent signals from the Eu 4f shell. The study serves as well to explore the limits of density functional theory and the choice of exchange correlation functionals to describe such a phenomenon as a valence transition.
Y1  - 2023
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/82460
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-824607
UR  - https://arxiv.org/abs/2209.10354v2
IS  - 22209.10354 Version 2
PB  - arXiv
ER  -