title: Role of hyperfine coupling in magnetic and quadrupolar ordering of Pr3Pd20Si6.
abstract: We study the ternary clathrate Pr3Pd20Si6 in specific heat and ac susceptibility measurements on a high-quality single crystal, distinguishing antiferromagnetic and antiferroquadrupolar ordering, as well as a hitherto unknown magnetic low-temperature transition. The specific heat shows the direct involvement of nuclear spin degrees of freedom in the antiferromagnetic ordering, which is well supported by our calculation of the hyperfine level scheme without adjustable parameters. Pr3Pd20Si6 is, therefore, one of the rare materials where the nuclear moments are involved in the formation of the magnetic ground state.
authors.affiliation: Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany. lucia@drs-steinke.de
authors.forename: L
authors.initials: L
authors.lastname: Steinke
authors.forename: K
authors.initials: K
authors.lastname: Mitsumoto
authors.forename: C F
authors.initials: CF
authors.lastname: Miclea
authors.forename: F
authors.initials: F
authors.lastname: Weickert
authors.forename: A
authors.initials: A
authors.lastname: Dönni
authors.forename: M
authors.initials: M
authors.lastname: Akatsu
authors.forename: Y
authors.initials: Y
authors.lastname: Nemoto
authors.forename: T
authors.initials: T
authors.lastname: Goto
authors.forename: H
authors.initials: H
authors.lastname: Kitazawa
authors.forename: P
authors.initials: P
authors.lastname: Thalmeier
authors.forename: M
authors.initials: M
authors.lastname: Brando