title: Contiguous 3d and 4f magnetism: strongly correlated 3d electrons in YbFe2Al10.
abstract: We present magnetization, specific heat, and (27)Al NMR investigations on YbFe2Al10 over a wide range in temperature and magnetic field. The magnetic susceptibility at low temperatures is strongly enhanced at weak magnetic fields, accompanied by a ln(T0/T) divergence of the low-T specific heat coefficient in zero field, which indicates a ground state of correlated electrons. From our hard-x-ray photoemission spectroscopy study, the Yb valence at 50 K is evaluated to be 2.38. The system displays valence fluctuating behavior in the low to intermediate temperature range, whereas above 400 K, Yb(3+) carries a full and stable moment, and Fe carries a moment of about 3.1 μB. The enhanced value of the Sommerfeld-Wilson ratio and the dynamic scaling of the spin-lattice relaxation rate divided by T[(27)(1/T1T)] with static susceptibility suggests admixed ferromagnetic correlations. (27)(1/T1T) simultaneously tracks the valence fluctuations from the 4f Yb ions in the high temperature range and field dependent antiferromagnetic correlations among partially Kondo screened Fe 3d moments at low temperature; the latter evolve out of an Yb 4f admixed conduction band.
authors.affiliation: Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Khuntia
authors.affiliation: Highly Correlated Matter Research Group, Physics Department, University of Johannesburg, P.O. Box 524, Auckland Park 2006, South Africa and Department of Physics, Eastern University, Vantharumoolai, Chenkalady 30350, Sri Lanka.
authors.forename: P
authors.initials: P
authors.lastname: Peratheepan
authors.affiliation: Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany and Highly Correlated Matter Research Group, Physics Department, University of Johannesburg, P.O. Box 524, Auckland Park 2006, South Africa.
authors.forename: A M
authors.initials: AM
authors.lastname: Strydom
authors.affiliation: Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany.
authors.forename: Y
authors.initials: Y
authors.lastname: Utsumi
authors.affiliation: Max Planck POSTECH Center for Complex Phase Materials, 01187 Dresden, Germany and Pohang 790-784, Korea.
authors.forename: K-T
authors.initials: KT
authors.lastname: Ko
authors.affiliation: National Synchrotron Radiation Research Center, 101 Hsin-Ann Road, Hsinchu 30077, Taiwan.
authors.forename: K-D
authors.initials: KD
authors.lastname: Tsuei
authors.affiliation: Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany.
authors.forename: L H
authors.initials: LH
authors.lastname: Tjeng
authors.affiliation: Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Steglich
authors.affiliation: Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Baenitz