Electronic structures of UTSn (T=Ni, Pd) using photoemission spectroscopy

TL;DR

This study investigates the electronic structures of UTSn compounds (T=Ni, Pd) using photoemission spectroscopy, revealing a reduced density of states at the Fermi level and minimal changes across magnetic transitions, with theoretical comparisons showing mixed agreement.

Contribution

It provides detailed photoemission spectra of UTSn compounds and compares experimental results with theoretical calculations, highlighting differences in electronic structures between Ni and Pd variants.

Findings

U 5f spectra show a broad peak at ~0.3 eV below E_F

Low N_f(E_F) correlates with low T d DOS near E_F

No significant electronic structure change across magnetic transitions

Abstract

The electronic structures of the localized $5f$ systems UTSn (T=Ni, Pd) have been investigated using photoemission spectroscopy (PES). The extracted U $5f$ PES spectra of UTSn (T=Ni, Pd) exhibit a broad peak centered at $\sim 0.3$ eV below $\rm E_F$ with rather small spectral weight near $\rm E_F$ (N$_f$($\rm E_F$)). The small N$_f$($\rm E_F$) in UTSn is found to be correlated with the T $d$ PES spectra that have a very low density of states (DOS) near $\rm E_F$. The high-resolution PES spectra for UTSn provide the V-shaped reduced metallic DOS near $\rm E_F$ but do not reveal any appreciable changes in their electronic structures across the magnetic phase transitions. A possible origin for the reduced N$_f$($\rm E_F$) in UTSn is ascribed to the hybridization to the very low T $d$ DOS at $\rm E_F$. Comparison of the measured PES spectra to the LSDA+$U$ band structure calculation reveals a reasonably good agreement for UPdSn, but not so for UNiSn.