Regensburg 2007 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 22: Low-dimensional Systems - Materials

TT 22.2: Vortrag

Donnerstag, 29. März 2007, 09:45–10:00, H18

Exotic Ground State of η-Na_9/7V₂O₅ — •Dmitry Zakharov^1,2, Hans-Albrecht Krug von Nidda¹, Günter Obermeier³, Siegfried Horn³, and Alois Loidl¹ — ¹EP V, EKM, University of Augsburg, 86135 Augsburg, Germany — ²Kazan State University, 420008 Kazan, Russia — ³EP II, Institut für Physik, Universität Augsburg, 86135 Augsburg, Germany

The nature of the ground gapped state in the novel quasi-one-dimensional compound η-Na_9/7V₂O₅ is rather mysterious, if one takes into account the odd number of spins on each structural element. Combining the results of specific heat, susceptibility, electron spin resonance and dielectric conductivity measurements we show that it can be understood in terms of multi-spin objects building up a linear chain. In spite of the small total spin, their spatial extent results in an exchange constant comparable to the one in the non-dimerized state.