title: Avoided ferromagnetic quantum critical point: unusual short-range ordered state in CeFePO.
abstract: Cerium 4f electronic spin dynamics in single crystals of the heavy-fermion system CeFePO is studied by means of ac susceptibility, specific heat, and muon-spin relaxation (μSR). Short-range static magnetism occurs below the freezing temperature T(g) ≈ 0.7 K, which prevents the system from accessing a putative ferromagnetic quantum critical point. In the μSR, the sample-averaged muon asymmetry function is dominated by strongly inhomogeneous spin fluctuations below 10 K and exhibits a characteristic time-field scaling relation expected from glassy spin dynamics, strongly evidencing cooperative and critical spin fluctuations. The overall behavior can be ascribed neither to canonical spin glasses nor other disorder-driven mechanisms.
authors.affiliation: Max-Planck-Institute for Chemical Physics of Solids, D-01187 Dresden, Germany. lausberg@cpfs.mpg.de
authors.forename: S
authors.initials: S
authors.lastname: Lausberg
authors.forename: J
authors.initials: J
authors.lastname: Spehling
authors.forename: A
authors.initials: A
authors.lastname: Steppke
authors.forename: A
authors.initials: A
authors.lastname: Jesche
authors.forename: H
authors.initials: H
authors.lastname: Luetkens
authors.forename: A
authors.initials: A
authors.lastname: Amato
authors.forename: C
authors.initials: C
authors.lastname: Baines
authors.forename: C
authors.initials: C
authors.lastname: Krellner
authors.forename: M
authors.initials: M
authors.lastname: Brando
authors.forename: C
authors.initials: C
authors.lastname: Geibel
authors.forename: H-H
authors.initials: HH
authors.lastname: Klauss
authors.forename: F
authors.initials: F
authors.lastname: Steglich
mesh_terms: D002563:Cerium / Q000737:chemistry*; D005290:Ferric Compounds / Q000737:chemistry*; D059346:Magnets; D008956:Models, Chemical; D010087:Oxides / Q000737:chemistry; D010758:Phosphorus / Q000737:chemistry; D011789:Quantum Theory
chemical_list: D005290:Ferric Compounds; D010087:Oxides; D010758:Phosphorus; D002563:Cerium