  We report the results of measurements of the dc-susceptibility and the
23Na-NMR response of Na2V2O7, a recently synthesized, non metallic low
dimensional spin system. Our results indicate that upon reducing the
temperature to below 100 K, the V^{4+} moments are gradually quenched, leaving
only one moment out of 9 active. The NMR data reveal a phase transition at very
low temperatures. With decreasing applied field H, the critical temperature
shifts towards T = 0 K, suggesting that Na2V2O7 may be regarded as an insulator
reaching a quantum critical point at H = 0.
