MAGNETIC-STRUCTURE IN THE ANTIFERROMAGNETIC STATE OF THE ORGANIC CONDUCTOR, (DME-DCNQI[3,3/1] D(7))(2)CU - H-1-NMR ANALYSIS

The antiferromagnetic state of the title compound has been investigated by the measurements of H-1-NMR lineshape and nuclear spin-lattice relaxation rate, T-1(-1), on a single crystal sample. Below the Neel temperature, T-N similar to 6.7 K, the resonance line was observed to split into three pairs of peaks. The angular dependence of the lineshape has revealed the magnetic structure of this compound; i) the antiferromagnetic moments are localized at Cu2+ sites and are regularly ordered with a three-fold periodicity along the stacking c-axis; ii) the easy axis is in the ab-plane and the c-axis is the hard axis; iii) a model of the three dimensional arrangement of the magnetic moments well explaining the experimental results is proposed.