book of abstracts - IM2NP

A B S T R A C T S WEDNESDAY, JUNE 30 N A N O S E A 2 0 1 0
9H10-9H30
Mechanism and compositions of GeMn self-assembled nanocolumns.
LE THANH (1 Centre Interdisciplinaire de Nanoscience de Marseille (CINaM-CNRS), Aix-Marseille
Université, Campus de Luminy, case 913, 13288 Marseille, France, 2 Department of Electronic Engineering, the
University of Electro-Communications, 1-5-1 Chofugaoka, Chofu-shi, Tokyo 182-8585, Japan)
9H30-9H50
DMRG approach to molecular-based alternating spin bimetallic chains.
DRZEWINSKI - P. Sobczak a , A. Barasiński b , R. Matysiak c , A. Drzewiński b , G.
Kamieniarz a , J. Kłak d , A. Bieńko d , J. Mroziński d , D. Gatteschi e (aFaculty of Physics, A.
Mickiewicz University, Poznań, Poland; bInstitute of Physics, University of Zielona Góra, Poland; cInstitute of
Engineering and Computer Education, University of Zielona Góra, Poland; dDepartment of Chemistry, University of
Wroclaw, Poland; dDepartment of Chemistry, University of Florence, Italy)
1 – Introduction
Molecular magnets, including bimetallic chain systems, can be numerically analysed on the basis of the
anisotropic quantum Heisenberg model [1]. To cover the entire experimental 1.7 − 300 K temperature range,
the density-matrix renormalization group (DMRG) approach is very appealing. It has been exploited in the
molecular nanomagnetism for the first time, analysing the experimental results for a number of compounds
with the thiocyanate bridges without the mean-field corrections [1].
2 – Abstract
At first, a series of one-dimensional compounds comprising square planar tetraazamacrocycle copper(II)
building blocks forming Cu(II)-SCN-M-NCS-Cu(II) chains, where M = Co, Ni, Mn, is reported. Although
the thiocyanate ligands are weak magnetic mediators, both the ferromagnetic and antiferromagnetic
interactions occur in our compounds and are not negligible [1]. The approach is applied also to the Re(IV) –
Cu(II) complex [Cu(tren)]ReCl 6·2CH 3 OH, where both the exchange interaction J and the D zero-field
splitting are expected to be much stronger [2].
The high accuracy results of our simulations have been fitted to the corresponding experimental
susceptibility and magnetization data. To get an appropriate set of parameters, we always fitted both the
magnetic susceptibility curves and the magnetization profiles to our numerical results.
[1] A. Barasinski et al, Polyhedron (2010), doi: 10.1016/j.poly.2010.01.002
[2] A. Tomkiewicz, et al, Journal of Molecular Structure 644, 97 (2003)
3 – Conclusion
For all the compounds, both the experimental susceptibility and field-dependent magnetization data have
been fitted successfully using the quantum model without the mean-field corrections, leading to the sets of
model parameters (the strength of magnetic couplings, the single-ion anisotropy terms and the corresponding
g factors). The corresponding values for the Re(IV) – Cu(II) compound are the following: J/k B = 3.5 ± 0.5 K,
D/k B = 35 ± 5 K, g Cu = 2.07 ± 0.05, g Re = 1.73 ± 0.01
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