DC-susceptibility and NMR response of a low-dimensional quantum magnet:: Na2V3O7

We report the results of DC-susceptibility and Na-23-NMR measurements on recently synthesized Na2V3O7. It has been suggested that this insulating material may be considered as a quasi-1D spin system, with localized spins S =(1)/(2) and one extra degree of freedom imposed by the crystal structure. The temperature dependence of the DC-susceptibility above 100K implies that each V ion has a spin; which is exposed to predominantly antiferromagnetic interactions. Below 100 K, however, the magnetic moments of 8 out of 9 V ions are quenched, most probably via a dimerization process. This process is completed near 35 K. The temperature dependence of the NMR spin-lattice relaxation rate reveals two well-defined peaks near ? and 90 K. (C) 2002 Elsevier Science B.V. All rights reserved.