title: Flux growth of Yb(6.6)Ir(6)Sn(16) having mixed-valent ytterbium.
abstract: The compound Yb6.6Ir6Sn16 was obtained as single crystals in high yield from the reaction of Yb with Ir and Sn run in excess indium. Single-crystal X-ray diffraction analysis shows that Yb6.6Ir6Sn16 crystallizes in the tetragonal space group P42/nmc with a = b = 9.7105(7) Å and c = 13.7183(11) Å. The crystal structure is composed of a [Ir6Sn16] polyanionic network with cages in which the Yb atoms are embedded. The Yb sublattice features extensive vacancies on one crystallographic site. Magnetic susceptibility measurements on single crystals indicate Curie-Weiss law behavior <100 K with no magnetic ordering down to 2 K. The magnetic moment within the linear region (<100 K) is 3.21 μB/Yb, which is ∼70% of the expected value for a free Yb(3+) ion suggesting the presence of mixed-valent ytterbium atoms. X-ray absorption near edge spectroscopy confirms that Yb6.6Ir6Sn16 exhibits mixed valence. Resistivity and heat capacity measurements for Yb6.6Ir6Sn16 indicate non-Fermi liquid metallic behavior.
authors.affiliation: New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research , Jakkur, Bangalore 560064, India.
authors.forename: Sebastian C
authors.initials: SC
authors.lastname: Peter
authors.forename: Udumula
authors.initials: U
authors.lastname: Subbarao
authors.forename: Sudhindra
authors.initials: S
authors.lastname: Rayaprol
authors.forename: Joshua B
authors.initials: JB
authors.lastname: Martin
authors.forename: Mahalingam
authors.initials: M
authors.lastname: Balasubramanian
authors.forename: Christos D
authors.initials: CD
authors.lastname: Malliakas
authors.forename: Mercouri G
authors.initials: MG
authors.lastname: Kanatzidis