Regensburg 2010 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 21: Magnetic Materials
MA 21.10: Vortrag
Mittwoch, 24. März 2010, 17:45–18:00, H23
Magnetic properties of the main group diradical ion 5,5’-Bis(1,2,3,4-trithiazolium) in a solid state matrix — •Manuel Presnitz1, Ernst-Wilhelm Scheidt1, Wolfgang Scherer1, and Jack Passmore2 — 1Lehrstuhl für Chemische Physik und Materialwissenschaften, Institut für Physik, Universität Augsburg, 86135 Augsburg, Germany — 2Department of Chemistry, University of New Brunswick, Fredericton NB E3B 6E2, Canada
The diradical nature of the main group molecule (CNSSS)2, systematic name 5,5’-Bis(1,2,3,4-trithiazolium), is remarkable because it is – like the prominent diradical O2 – a non sterically hindered main group compound, which retains its paramagnetic characteristics also in the solid state. Here the (CNSSS)2 diradical ions are embedded in a PnF6 (Pn=As, Sb) matrix.
The specific heat C(T) and magnetic susceptibility χ(T) data (for SbF6 matrix) show some irreversible behavior during the first cooling stage down to 2 K. By subsequent heating/cooling cycles different states seem to be accessible until a final reversible behavior (χrev) is observed.
The magnetic susceptibility of different model systems was fitted to χrev but the distinction between an alternating spin chain (Johnston et al.) and spin ladder (Barnes/Riera) is not possible based on experimental results for χ(T) only. Hence, to gain deeper insight into the magnetic coupling mechanism, our χ(T) measurements are complemented by ab initio calculations to obtain inter- and intra-molecular coupling constants and disqualify one of the models.