Regensburg 2007 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 22: Low-dimensional Systems - Materials
TT 22.13: Vortrag
Donnerstag, 29. März 2007, 12:45–13:00, H18
CuSe2O5 – a new quasi one-dimensional spin-1/2 Heisenberg system — •Oleg Janson1,2, Walter Schnelle1, Marcus Schmidt1, Stefan-Ludwig Drechsler3, and Helge Rosner1 — 1MPI CPfS Dresden, Germany — 2St. Petersburg State University, Russia — 3IFW Dresden, Germany
We report a joined experimental and theoretical study of the new quasi
one-dimensional spin-1/2 Heisenberg system CuSe2O5. Its crystal
structure is characterized by chains of canted isolated CuO4
plaquettes aligned along the c axis of the monoclinic lattice,
raising the question about the size of the different exchange
couplings between the CuO4 units. Combining measurements of the
magnetic susceptibility χ and specific heat cp with DFT band
structure calculations, we analyze the magnetic properties and the
leading exchange interactions of this compound. The single crystals of CuSe2O5
were grown by chemical vapour transport using TeCl4 as transport
agent. Our χ and cp data indicate a phase transition to long
range antiferromagnetic order at TN ∼ 17K. From a tight-binding
analysis of the electronic structure and from total energy
calculations for constraint magnetic states we can describe the system
in good approximation by a nearest neighbour exchange J1 ∼ 20 meV
along the structural chains and a sizable inter-chain coupling
J⊥∼ 5 meV in good agreement with the experimental results.
The Emmy-Noether program is acknowledged for financial support.