Yb4LiGe4 – A Yb mixed valent Zintl phase with strong electronic correlations

Abstract

a b s t r a c tSingle-phase samples of Yb 4 LiGe 4 and Yb 5 Ge 4 were synthesized using high frequency (HF) heat treatment. Yb 4 LiGe 4 crystallizes in orthorhombic space group Pnma with the Gd 5 Si 4 type of crystal structure and lattice parameters a = 7.0828(3)Å, b = 14.6415(7)Å, and c = 7.6279(4)Å. One Yb position in Yb 5 Ge 4 is substituted by the lithium atom and causes a distortion of the germanium tetragons in Yb 4 LiGe 4 . Investigation of the electronic state of Yb via magnetic susceptibility and X-ray absorption near-edge spectroscopy (XANES) revealed a presence of two electronic states of ytterbium, 4f 13 and 4f 14 (mixed valence), in Yb 5 Ge 4 and Yb 4 LiGe 4 . Studies of the temperature dependence of the electrical resistivity, magnetization, 7 Li spin-lattice relaxation rate and the specific heat indicate that strong electronic correlations are present in Yb 4 LiGe 4 , and below approximately 50 K there is a competition between ferromagnetic and antiferromagnetic correlations. Magnetic ordering in Yb 4 LiGe 4 , if present, occurs below the reported antiferromagnetic transition temperature of 1.7 K for Yb 5 Ge 4 .

Synthetically Tuned Atomic Ordering in PdCu Nanoparticles with Enhanced Catalytic Activity toward Solvent-Free Benzylamine Oxidation

“…Typically, IMCs are synthesized at high temperature by arc melting, ceramic, and high-frequency induction heating methods. − The formation of the ordered compounds required high temperature, as it demands high kinetic energy for the better diffusion of the reactants. On the one hand, increase in reaction temperature favors better thermal vibration of the atoms, which enhances the diffusion of the metals and results in the ordered compounds .…”

Flux Growth of Yb6.6Ir6Sn16 Having Mixed-Valent Ytterbium

“…The structural diversity of the Yb 5 Ir 5.5 Sn 18 compound and our continued interest in ytterbium-based intermetallic compounds, − which is based on the valence flexibility of ytterbium, allowing it to adopt different or mixed oxidation states, − motivates our current work. The presence of an unstable electronic 4 f shell can cause the Yb ion to show two electronic configurations that are closely spaced in energy: the magnetic Yb 3+ (4 f 13 ) and the nonmagnetic Yb 2+ (4 f 14 ).…”

Yb7Ni4InGe12: a quaternary compound having mixed valent Yb atoms grown from indium flux

“…46,47 These properties are generally believed to arise from the strong hybridization (interaction) between the localized 4f electrons and the delocalized s, p, d conduction electrons. [48][49][50] In the last several years, we have focused our research on the intermetallic chemistry of Yb based compounds [51][52][53][54][55] and sought deeper understanding of the ability of Yb to adopt different structure types. During the systematic studies on the compounds in the Yb-Ni-Ge family, a new quaternary compound Yb 7 Ni 4 InGe 12 was obtained from the reaction run in In flux.…”