Magnetic-Field Induced Slow Relaxation in the Ising-Like Quasi-One-Dimensional Ferromagnet KEr(MoO4)2
V. Tkáč a, A. Orendáčováa, L'. Dlháň b, M. Orendáč a, R. Boča c and A. Feher a
aCentre of Low Temperature Physics of SAS and P.J. Šafárik University, Park Angelinum 9, 04001 Košice, Slovak Republic
bInstitute of Inorganic Chemistry, FCHPT, Slovak University of Technology, 812 37 Bratislava, Slovakia
cDepartment of Chemistry, FPV, University of SS Cyril and Methodius, 917 01 Trnava, Slovakia
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We present the study of spin dynamics of KEr(MoO4)2 in the magnetic field applied along the hard axis c. The temperature dependence of AC susceptibility in zero magnetic field studied at frequencies f=10, 100, and 1000 Hz indicated the absence of relaxation in the temperature range from 2 to 20 K. Application of magnetic field induced a slow magnetic relaxation, which was investigated in detail in the field 0.5 T. The highest intensity of the relaxation process, reflected by the values of imaginary susceptibility was observed at 2 K. With increasing temperature, the relaxation process is weaker and vanishes completely above 3.5 K. Corresponding Cole-Cole diagrams were constructed and analyzed within a single relaxation process which can be associated with a direct relaxation process with a bottleneck effect, τ ≈1/Tb, and b=1.4. The slow relaxation at 2 K intensifies with increasing magnetic field at least up to 1 T.

DOI: 10.12693/APhysPolA.131.893
PACS numbers: 76.60.Es, 76.30.Kg, 75.30.Gw, 75.40.Gb