Dresden 2009 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 6: Postersession Correlated Electrons: (General) Theory, Low-Dimensional Systems, Kondo Physics, Heavy Fermions, Quantum-Critical Phenomena
TT 6.25: Poster
Montag, 23. März 2009, 13:00–16:45, P1A
Magnetic properties of the new low dimensional S=1/2 system: Cu(NO3)2 ·H2O — M. Yehia1, E. Vavilova1,2, •V. Kataev1, R. Klingeler1, O. Volkova3,4, E. Lapsheva4, V. Shutov4, O. Savelieva4, A.N. Vasiliev4, and B. Büchner1 — 1Institute for Solid State Physics, IFW Dresden, 01171 Dresden, Germany. — 2Kazan Physical Technical Institute, Russian Academy of Sciences, 420029 Kazan, Russia. — 3Institute of Radiotechnics and Electronics, 125009 Moscow, Russia. — 4Moscow State University, 119991 Moscow, Russia.
The new low dimensional S=1/2 system Cu(NO3)2 ·H2O is studied by ESR (9.5 GHz), magnetic susceptibility χ (T), specific heat Cp (T) and NMR. The anisotropy of the ESR measureables reveals a two dimensional nature of the Cu2+(S = 1/2) layers in this material. The T-dependence of the ESR response for different field directions indicates a substantial magnetic anisotropy and occurrence of different exchange paths in the Cu layers. A phase transition of antiferromagnetic nature at TN ∼ 3.4 K can be identified in the χ (T) data. This is consistent with the specific heat measurements which exhibit a peak at 3.4 K in zero magnetic field. However, an application of an external field of 3 T strongly suppresses this peak. In addition, a broad anomaly has been observed at low temperatures in the Cp (T) data. On the basis of our experimental data we discuss the interplay between the structure and magnetism of this novel compound.