Regensburg 2004 – wissenschaftliches Programm

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MA: Magnetismus

MA 21: Bio- und molekularer Magnetismus

MA 21.1: Vortrag

Donnerstag, 11. März 2004, 10:15–10:30, H22

Physics of a new copper-based triangular chain — •Jürgen Schnack¹, Hiroyuki Nojiri², Paul Kögerler³, and Leroy Cronin⁴ — ¹Universität Osnabrück, Fachbereich Physik, D-49069 Osnabrück, Germany — ²Dept. of Physics, Okayama University, Tsushimanaka 3-1-1, Okayama, 700-8530 Japan — ³Ames Laboratory, Iowa State University, Ames, Iowa 50011, USA — ⁴Dept. of Chemistry, The University of Glasgow, Glasgow, G12 8QQ, UK

We report the synthesis and magnetic characterization of a new class of one-dimensional chains of antiferromagnetically coupled copper triangles. Since the copper triangles are coupled via hydrogen bonds, which naively are assumed to be weak exchange pathways, one expects that the chain shows a pronounced plateau at 1/3 of the saturation magnetization. The high field magnetization curve shows, however, no plateau. The observed magnetization and susceptibility curves are successfully interpreted by a theoretical model, in which the inter- and intra-triangle exchange parameters are of similar size. In effect the infinite chain turns out to be an interesting example of a frustrated spin system with competing interactions.