Electronic structure and crystallographic properties of skutterudite-related Ce${}_{3}{M}_{4}$Sn${}_{13}$ and La${}_{3}{M}_{4}$Sn${}_{13}$ ($M=\mathrm{Co}$, Ru, and Rh)

Electronic structure and crystallographic properties of skutterudite-related Ce $_{3} M_{4}$ Sn $_{13}$ and La $_{3} M_{4}$ Sn $_{13}$ ( $M = Co$ , Ru, and Rh)

A. Ślebarski and J. Goraus

Phys. Rev. B 88, 155122 – Published 21 October 2013

Abstract

The structural and electronic properties of the skutterudite-related Ce $_{3}$ $M$ $_{4}$ Sn $_{13}$ and La $_{3}$ $M$ $_{4}$ Sn $_{13}$ intermetallic compounds with $M = Co$ , Ru, and Rh have been investigated. A subtle structural transition from a simple cubic phase (Yb $_{3}$ Rh $_{4}$ Sn $_{13}$ -type structure) to the superlattice variant at $T_{D} \sim 160$ K has been evidenced by x-ray diffraction, resistivity, and specific-heat data. Recently, a high charge density between metal $M$ and Sn atoms was calculated for Ce $_{3}$ Rh $_{4}$ Sn $_{13}$ and Ce $_{3}$ Co $_{4}$ Sn $_{13}$ . The strong charge accumulation implies a strong $M$ -Sn2 covalent bonding interaction. In consequence, a local distortion of the trigonal Sn prisms around metal $M$ can modify the electronic structure of the system. The main goal of this report is to study the electronic structure in the family of RE $_{3}$ $M$ $_{4}$ Sn $_{13}$ , where $RE = Ce$ or La above and below $T_{D}$ . We show that the Sn $4 d$ x-ray photoelectron spectroscopy spectra have the complex structure, which can be interpreted as a result of different charge distribution around Sn atoms. The shape of the $4 d$ Sn lines is also temperature dependent, which we attribute to the local distortion of the Sn2 cages in RE $_{3}$ $M$ $_{4}$ Sn $_{13}$ .