Magnetocaloric Study of S=1/2 Low-Dimensional Heisenberg Antiferromagnet [Cu(phen)(H2 O)2 ]SO4 |
| L. Sedláková, M. Orendáč, M. Kajňaková, A. Orendáčová and A. Feher
Centre of Low Temperature Physics, Faculty of Science, P.J. Šafárik University and Institute of Physics, SAS, Park Angelinum 9, 041 54 Košice, Slovakia |
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| Received: 9 07 2007; |
| We present the experimental study of magnetocaloric effect on powder sample [Cu(phen)(H2 O)2 ]SO4 (phen = phenantroline = C12 H8 N2 ) in the temperature range from nominally 0.2 K to 4 K and in magnetic fields up to 2 T. The values of total entropy were extracted from the experimental data obtained by adiabatic demagnetization. The comparison was performed with the temperature dependence of the entropy for S=1/2 paramagnet calculated at selected magnetic fields. The deviations observed below 0.6 T were attributed to internal field mediated by exchange coupling. In addition, the temperature response observed in [Cu(phen)(H2 O)2 ]SO4 revealed very short relaxation time below 1 K. The comparison of the behavior observed at the end of the demagnetization in [Cu(phen)(H2 O)2 ]SO4 and other systems suggests that the magnetocaloric effect can serve as an alternative tool for studying slow magnetic relaxation. |
| DOI: 10.12693/APhysPolA.113.473 PACS numbers: 75.30.Sg, 75.50.Ee |