Valence fluctuations of europium in the boride Eu4Pd29+xB8. (19th February 2016)

• Record Type: Journal Article
• Authors: Gumeniuk, Roman; Schnelle, Walter; Ahmida, Mahmoud A; Abd-Elmeguid, Mohsen M; Kvashnina, Kristina O; Tsirlin, Alexander A; Leithe-Jasper, Andreas; Geibel, Christoph
• Is Part Of: Journal of physics. Volume 28:Number 11(2016)
• Publication Date: 2016-02-19
• Subjects: crystal structure -- valence fluctuations -- magnetism -- Kondo system; Condensed matter -- Periodicals; Matière condensée -- Périodiques; Vaste stoffen; Vloeistoffen; Natuurkunde; Electronic journals; Computer network resources; 530.4105
• DOI: 10.1088/0953-8984/28/11/115601
• Languages: English
• ISSNs: 0953-8984

Abstract

Abstract: We synthesized a high-quality sample of the boride Eu4 Pd29+ x B8 ( x = 0.76) and studied its structural and physical properties. Its tetragonal structure was solved by direct methods and confirmed to belong to the Eu4 Pd29 B8 type. All studied physical properties indicate a valence fluctuating Eu state, with a valence decreasing continuously from about 2.9 at 5 K to 2.7 at 300 K. Maxima in the T dependence of the susceptibility and thermopower at around 135 K and 120 K, respectively, indicate a valence fluctuation energy scale on the order of 300 K. Analysis of the magnetic susceptibility evidences some inconsistencies when using the ionic interconfigurational fluctuation (ICF) model, thus suggesting a stronger relevance of hybridization between 4 f and valence electrons compared to standard valence-fluctuating Eu systems.