Electronic structure ofSrPt4Ge12: Combined photoelectron spectroscopy and band structure study

Abstract

We present a combined study of the electronic structure of the superconducting skutterudite derivative SrPt4Ge12 by means of X-ray photoelectron spectroscopy and full potential band structure calculations including an analysis of the chemical bonding. We establish that the states at the Fermi level originate predominantly from the Ge 4p electrons and that the Pt 5d shell is effectively full. We find excellent agreement between the measured and the calculated valence band spectra, thereby validating that band structure calculations in combination with photoelectron spectroscopy can provide a solid basis for the modeling of superconductivity in the compounds M Pt4Ge12 (M = Sr, Ba, La, Pr) series.

Insulator-metal transition in TiGePt: A combined photoelectron spectroscopy, x-ray absorption spectroscopy, and band structure study

“…In TiGePt the Pt 4f peaks are shifted by 1.1-1.3 eV to higher binding energies in comparison to those of Pt metal. Similar shifts have also been observed in other noble-metal intermetallic compounds, [19][20][21][22] indicating a lowered averaged electron density around the noble-metal sites. To compare this chemical shift to the results of LDA calculations, one has to take into account that LDA does not incorporate many-body effects of the final state, as manifested in the asymmetric line shape in the spectra of the elemental Pt, as we will discuss below in more detail.…”

Electronic Structure of the Novel Filled Skutterudite PrPt4Ge12Superconductor

“…Thus nearly identical spectral shape of the two compounds is mostly due to the similarity of their identical electronic structures derived from the Pt-Ge framework. Moreover, the PES spectrum of SrPt 4 Ge 12 also shows a very similar spectral shape, 13) indicating that the electronic structure derived from the Pt-Ge framework is independent of M atoms in the filled skutterudite compounds in the first approximation.…”

Magnetic order in the filled skutteruditesRPt4Ge12(R= Nd, Eu)

“…Experimental and theoretical analysis of the electronic structure and chemical bonding revealed deep-lying Pt 5d states which only partially form covalent bands with the Ge 4p electrons. Consequently, the states at the Fermi level, which are relevant for superconductivity of these compounds, can be assigned to originate mainly from Ge 4p electrons [12]. Here, we report on the low-temperature magnetic properties of RPt 4 Ge 12 (R = Nd, Eu) studied by specific heat, dc-susceptibility, and magnetization experiments.…”