title: Slow spin relaxation induced by magnetic field in [NdCo(bpdo)(H2O)4(CN)6]⋅3H2O.
abstract: We report on a comprehensive investigation of the magnetic properties of [NdCo(bpdo)(H2O)4(CN)6]⋅3H2O (bpdo=4, 4'-bipyridine-N,N'-dioxide) by use of electron paramagnetic resonance, magnetization, specific heat and susceptibility measurements. The studied material was identified as a magnet with an effective spin S = 1/2 and a weak exchange interaction J/kB = 25 mK. The ac susceptibility studies conducted at audio frequencies and at temperatures from 1.8 to 9 K revealed that the application of a static magnetic field induces a slow spin relaxation. It is suggested that the relaxation in the magnetic field appears due to an Orbach-like process between the two lowest doublet energy states of the magnetic Nd(3+) ion. The appearance of the slow relaxation in a magnetic field cannot be associated with a resonant phonon trapping. The obtained results suggest that the relaxation is influenced by nuclear spin driven quantum tunnelling which is suppressed by external magnetic field.
authors.affiliation: Centre of Low Temperature Physics, P J Šafárik University and IEP SAS, Park Angelinum 9, SK-04154 Košice, Slovakia.
authors.forename: P
authors.initials: P
authors.lastname: Vrábel
authors.forename: M
authors.initials: M
authors.lastname: Orendáč
authors.forename: A
authors.initials: A
authors.lastname: Orendáčová
authors.forename: E
authors.initials: E
authors.lastname: Čižmár
authors.forename: R
authors.initials: R
authors.lastname: Tarasenko
authors.forename: S
authors.initials: S
authors.lastname: Zvyagin
authors.forename: J
authors.initials: J
authors.lastname: Wosnitza
authors.forename: J
authors.initials: J
authors.lastname: Prokleška
authors.forename: V
authors.initials: V
authors.lastname: Sechovský
authors.forename: V
authors.initials: V
authors.lastname: Pavlík
authors.forename: S
authors.initials: S
authors.lastname: Gao
mesh_terms: D002248:Carbon Monoxide / Q000737:chemistry*; D004578:Electron Spin Resonance Spectroscopy; D008280:Magnetics; D008958:Models, Molecular; D009354:Neodymium / Q000737:chemistry*; D011725:Pyridines / Q000737:chemistry*; D011789:Quantum Theory; D015204:Spectroscopy, Mossbauer; D013113:Spin Labels; D013696:Temperature; D014867:Water / Q000737:chemistry*
chemical_list: D011725:Pyridines; D013113:Spin Labels; D014867:Water; D009354:Neodymium; D002248:Carbon Monoxide