title: Physical properties and valence state of cerium in the filled skutterudite CePt₄Ge₁₂.
abstract: Electronic, magnetic, and transport properties of the filled platinum-germanium skutterudite CePt₄Ge₁₂ are investigated. High resolution x-ray absorption spectroscopy measurements at the cerium L(III) edge demonstrate that CePt₄Ge₁₂ in this compound has a temperature-independent valence close to three. However, magnetic susceptibility, thermopower, Hall effect, and electronic specific heat reveal a broad maximum at Tmax D 65-80 K, suggesting the presence of valence fluctuations. The Sommerfeld coefficient γ = 105 mJ mol⁻¹ K⁻², deduced from specific heat, indicates moderately enhanced band masses for CePt₄Ge₁₂. We discuss these findings and conclude that CePt₄Ge₁₂ represents a system at the border between intermediate valence (IV) and Kondo lattice behavior. In addition, the lattice specific heat and the thermal conductivity are discussed with respect to the vibrational dynamics of Ce in the [Pt₄Ge₁₂] framework.
authors: Max-Planck-Institut für Chemische Physik fester Stoffe, 01187 Dresden, Germany.
authors: R
authors: R
authors: Gumeniuk
authors: K O
authors: KO
authors: Kvashnina
authors: W
authors: W
authors: Schnelle
authors: M
authors: M
authors: Nicklas
authors: H
authors: H
authors: Borrmann
authors: H
authors: H
authors: Rosner
authors: Y
authors: Y
authors: Skourski
authors: A A
authors: AA
authors: Tsirlin
authors: A
authors: A
authors: Leithe-Jasper
authors: Yu
authors: Y
authors: Grin