Electronic Structure of the Novel Filled Skutterudite PrPt₄Ge₁₂Superconductor

Abstract

We have performed soft x-ray photoemission spectroscopy (SXPES) and resonant photoemission spectroscopy (RPES) of the filled skutterudite superconductor PrPt 4 Ge 12 in order to study the electronic structure of valence band and the character of Pr 4f . SXPES of

Comparative photoemission studies on the superconducting gap of the filled skutterudite superconductors LaPt4Ge12and PrPt4Nakamura1, Okazaki2, Yoshida3 et al. 2012Phys. Rev. BSelf Cite246221View full textAdd to dashboardCite

“…According to band structure calculations, the states near the E F of LaPt 4 Ge 12 and PrPt 4 Ge 12 have a dominant Ge 4p character hybridized with Pt 5d. 5 Resonant PES studies of PrPt 4 Ge 12 do not show significant enhancement of the spectral intensity near E F across the Pr 3d-to-4f threshold, 14 in contrast with similar studies of PrFe 4 P 12 , which is considered to be a heavy fermion material with significant hybridization of the conduction band and 4f electrons. 15 The spectrum at 4K (the superconducting state) of each compound shows a reduced intensity near the E F region and a peak at 2 meV.…”

First-principles study of the electronic structure and the Fermi surface in rare-earth filled skutterudites RPt4Ge12

“…In this figure we also show the comparison of our calculations with the available experimental soft X-ray photoemission spectra 55 . We digitized the experimental data and we plot it on top of our calculated DOS in Fig.…”

“…5b where we show the digitized data from Ref. 55 for two incident energies, 1.2 and 0.9 KeV. For incident energy of 1.2 KeV we probe mostly the Pt d states (magenta curve) and for incident energy of 0.9 KeV, in addition to Pt d states, we also probe the Pr f states (black curve).…”

“…But, several other experiments point to multi-band superconductivity with two superconducting gaps. Lower and upper critical field measurements and photoemission spectroscopy (PES) 41,42 , and upturn in temperature dependence of upper critical field 28,40,43 indicate multi-band paring. Strong indication of two-gap superconductivity (as in MgB 2 32, 33,44,45 and Pb 34,35,46 ) has been found in the analysis of superfluid density in single crystal PrPt 4 Ge 12 29 , the only single crystal measurement in this material that we are aware of.…”

“…We see that when comparing the experimental data with the total DOS per formula unit, by construction we get a good agreement for the energy range around -4 eV, but the agreement is poor for energy closer to the E F . The reason for this discrepancy is the fact that the photoemission spectra were measured at an incident energy of 1.2 KeV, energy where mostly Pt d states were probed, the other states practically being invisible to this probe due to the very small scattering cross-section at this energy 55 . These discrepancies are expected since the total DOS per formula unit is a sum of all states with equal probability without considering the experimental scattering cross-sections.…”