title: Multiple-timescale relaxation dynamics in CsGd(MoO4)2--a dipolar magnet with a highly anisotropic layered crystal structure.
abstract: The dynamic properties of the dipolar magnet CsGd(MoO4)2 have been studied. The frequency and temperature dependence of the AC susceptibility investigated in the paramagnetic region above 2 K revealed the co-existence of magnetic field induced slow and fast relaxation channels with a timescale differing by three orders of magnitude. The slow relaxation is determined by the properties of the first coordination sphere of the Gd(3+) ion and has the character of a two-phonon Orbach process. The fast relaxation is potentially attributed to a two-phonon Raman process realized via a localized phonon mode associated with the layered crystal structure. The temperature dependence of the phonon mean free path in zero magnetic field indicates significant phonon scattering below 1 K resulting from the combined effect of magnetic correlations and the scattering of dominant phonons with energies corresponding to the crystal-field levels.
authors.affiliation: Institute of Physics, P J Šafárik University, Park Angelinum 9, 04001 Košice, Slovak Republic.
authors.forename: V
authors.initials: V
authors.lastname: Tkáč
authors.forename: A
authors.initials: A
authors.lastname: Orendáčová
authors.forename: R
authors.initials: R
authors.lastname: Tarasenko
authors.forename: E
authors.initials: E
authors.lastname: Cižmár
authors.forename: M
authors.initials: M
authors.lastname: Orendáč
authors.forename: K
authors.initials: K
authors.lastname: Tibenská
authors.forename: A G
authors.initials: AG
authors.lastname: Anders
authors.forename: S
authors.initials: S
authors.lastname: Gao
authors.forename: V
authors.initials: V
authors.lastname: Pavlík
authors.forename: A
authors.initials: A
authors.lastname: Feher
mesh_terms: D016880:Anisotropy; D002586:Cesium / Q000737:chemistry*; D003460:Crystallization; D003461:Crystallography; D005682:Gadolinium / Q000737:chemistry*; D060526:Magnetic Fields; D059346:Magnets / Q000737:chemistry*; D008982:Molybdenum / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry*; D060739:Phonons; D013059:Spectrum Analysis, Raman
chemical_list: D010087:Oxides; D002586:Cesium; D008982:Molybdenum; D005682:Gadolinium