High field NMR studies of NaV2O5 to 44.7 T

Na-23 NMR Studies have been carried out to map the uniform to dimerized phase boundary up to 44.7 T in the NHMFL hybrid. The transition is observed by the splitting of the NMR line (H//a axis) by the lattice distortion. The field dependence Of T, Up to 44.7 T, in agreement with previous magnetization data to 30 T, is very small (alpha=0.092) compared to 0.4 for conventional SP systems and shows no deviation within experimental error from the h(2) dependence, while optical data show a decrease of the slope in the H-T phase diagram beginning around 40 T. The region of an anomaly near T 33 T and 32 K observed in optical data taken in the long pulse magnet at LANL(1) was also explored. Tie only evidence in the NMR of the observed optical anomaly near 33 T and 32 K was line broadening over a 2 T interval.