[Zurück]

K. Removic-Langer, V. Pashchenko, A. Prokofiev, B. Wolf, M. Lang, J. Schreuer, L. Wiehl, E. Haussühl, B. Winkler:
"Structural and magnetic properties of oxalate-bridged low-dimensional Cu²⁺ spin systems";
Poster: Frühjahrstagung der Deutschen Physikalischen Gesellschaft (DPG), Dresden, Deutschland; 26.03.2006 - 31.03.2006.

TT 25.14 Wed 14:30 P1

Structural and magnetic properties of oxalate-bridged
low-dimensional Cu2+ spin systems -
Katarina Removi´c- Langer1, Volodymyr Pashchenko1, Andrey Prokofiev1,
Bernd Wolf1, Michael Lang1, J¨urgen Schreuer2, Leonore
Wiehl2, Eiken Hauss¨uhl2, and Bj¨orn Winkler2 - 1Physikalisches
Institut, J. W. Goethe-Universit¨at, FOR 412, Max-von-Laue-Str.
1, D-60438 Frankfurt(M), Germany - 2Institut f¨ur Mineralogie/
Kristallographie, J. W. Goethe-Universit¨at, FOR 412, Senckenberganlage
30, D-60054 Frankfurt(M), Germany

Our study focused on the structural and magnetic properties of two
1,10-bicoordinated oxalate-bridged Cu2+ spin chains, [Cu(μ-ox)-(H2O)(4-
apy)2]n (1) and [(pyOH)Cu(ox)-H2O]n (2). While in 1 all oxalate
molecules are in the bis-monodentate configuration, compound 2 is built
from two non-equivalent ox molecules which alternate in the bis-bidentate
form along the chain. The Cu atoms of compound 1 are in a distorted
square-pyramidal environment while those in compound 2 are in a distorted
octahedral configuration. Magnetic measurements reveal the behavior
of a uniform Heisenberg spin chain with a small antiferromagnetic
(AF) exchange coupling constant of J 3K for 1, consistent with [1],
and that of a dimer system with predominant AF intradimer interaction
of J 403K and only weak interdimer couplings for 2. The nature and
magnitude of the magnetic coupling through the oxalate bridges in 1 and
2 will be discussed in the light of available structural data.