title: Introducing a magnetic guest to a tetrel-free clathrate: synthesis, structure, and properties of Eu(x)Ba(8-x)Cu16P30 (0 ≤ x ≤ 1.5).
abstract: The europium-containing clathrate-I Eu(x)Ba(8-x)Cu(16)P(30) was synthesized from the elements. Powder X-ray diffraction in combination with energy dispersive X-ray absorption spectroscopy (EDXS) and metallographic studies showed the homogeneity range with x ≤ 1.5. Determination of the crystal structure confirmed the presence of an orthorhombic superstructure of clathrate-I and revealed that Eu atoms exclusively resided in small pentagonal-dodecahedral cages. Magnetic measurements together with X-ray absorption spectroscopy are consistent with a 4f(7) (Eu(2+)) ground state for Eu(x)Ba(8-x)Cu(16)P(30). Below 3 K the Eu moments order antiferromagnetically. Resistivity measurements revealed metallic behavior of the investigated clathrate, in line with the composition deviating from the Zintl counting scheme. Local vibrations of the guest atoms inside the cages are analyzed with the help of specific heat investigations.
authors: Max-Planck-Institut für Chemische Physik fester Stoffe, Nöthnitzer Straße 40, 01187 Dresden, Germany. kkovnir@ucdavis.edu
authors: Kirill
authors: K
authors: Kovnir
authors: Ulrike
authors: U
authors: Stockert
authors: Sergij
authors: S
authors: Budnyk
authors: Yurii
authors: Y
authors: Prots
authors: Michael
authors: M
authors: Baitinger
authors: Silke
authors: S
authors: Paschen
authors: Andrei V
authors: AV
authors: Shevelkov
authors: Yuri
authors: Y
authors: Grin