title: Field-induced suppression of the heavy-fermion state in YbRh2Si2.
abstract: We report dc-magnetization measurements on YbRh2Si2 at temperatures down to 0.04 K, magnetic fields B< or =11.5 T, and under hydrostatic pressure P< or =1.3 GPa. At ambient pressure a kink at B* =9.9 T indicates a new type of field-induced transition from an itinerant to a localized 4f state. This transition is different from the metamagnetic transition observed in other heavy-fermion compounds, as here ferromagnetic rather than antiferromagnetic correlations dominate below B*. Hydrostatic pressure experiments reveal a clear correspondence of B* to the characteristic spin fluctuation temperature determined from specific heat.
authors.affiliation: Max-Planck-Institute for Chemical Physics of Solids, D-01187 Dresden, Germany.
authors.forename: Y
authors.initials: Y
authors.lastname: Tokiwa
authors.forename: P
authors.initials: P
authors.lastname: Gegenwart
authors.forename: T
authors.initials: T
authors.lastname: Radu
authors.forename: J
authors.initials: J
authors.lastname: Ferstl
authors.forename: G
authors.initials: G
authors.lastname: Sparn
authors.forename: C
authors.initials: C
authors.lastname: Geibel
authors.forename: F
authors.initials: F
authors.lastname: Steglich