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

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 ${\mathrm{E}}_{\mathrm{F}}$ with rather small spectral weight near ${\mathrm{E}}_{\mathrm{F}}$ (N${}_f$(${\mathrm{E}}_{\mathrm{F}}$)). The small N${}_f$(${\mathrm{E}}_{\mathrm{F}}$) in UTSn is found to be correlated with the T $d$ PES spectra that have a very low density of states (DOS) near ${\mathrm{E}}_{\mathrm{F}}$. The high-resolution PES spectra for UTSn provide the V-shaped reduced metallic DOS near ${\mathrm{E}}_{\mathrm{F}}$ but do not reveal any appreciable changes in their electronic structures across the magnetic phase transitions. A possible origin for the reduced N${}_f$(${\mathrm{E}}_{\mathrm{F}}$) in UTSn is ascribed to the hybridization to the very low T $d$ DOS at ${\mathrm{E}}_{\mathrm{F}}$. 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.

7 pages, 6 figures