51V and133Cs NMR Study of a Quasi-One-Dimensional Triangular Lattice Antiferromagnet CsVCl3

The 51 V and 133 Cs NMR study has been performed in order to obtain the information on the spin state of a single crystal of CsVCl 3 . In the ordered state the 51 V NMR signal was observed around 106.5 MHz at 4.2 K and at zero external field. From this the spin reduction associated with the V 2+ ions was estimated to be 71%. The observed external field dependence of the 51 V spectrum could not be explained from the simple 120° Néel model proposed by the neutron diffraction experiment. In the paramagnetic state, the quadrupole split resonance lines of the 133 Cs signals were observed, which were broadened into a spectrum characteristic of the two-dimensional powder pattern in the ordered state. The spectrum could be reproduced by a modified 120° Néel structure.