Chain formation by spin pentamers in -Na9V14O35D. V. Zakharov1, H.-A. Krug von Nidda1, J. Deisenhofer1, F. Schrettle1, G. Obermeier2, S. Horn2 and A. Loidl1
1 Experimental Physics V, Center for Electronic Correlations and Magnetism, University of Augsburg Universitätsstraße 2, 86135 Augsburg, Germany, EU
2 Experimentalphysik II, Institut für Physik, Universität Augsburg - Universitätsstraße 2, 86135 Augsburg, Germany, EU
received 14 April 2008; accepted in final form 24 July 2008; published September 2008
published online 2 September 2008
The nature of the gapped ground state in the quasione-dimensional compound -Na9V14O35 cannot easily be understood, if one takes into account the odd number of spins on each structural element. Combining the results of specific heat, susceptibility and electron spin resonance measurements, we show that -Na9V14O35 exhibits a novel ground state where multi-spin objects build up a linear chain. These objects —pentamers— consist of five antiferromagnetically arranged spins with effective spin 1/2. Their spatial extent results in an exchange constant along the chain direction comparable to the one in the high-temperature state.
76.30.-v - Electron paramagnetic resonance and relaxation.
65.40.Ba - Heat capacity.
75.10.Pq - Spin chain models.
© EPLA 2008