Low-dimensional V-based complex oxides: an NMR study

We performed 31P and 51V NMR study of low-dimensional isostructural compounds Sr2V3O9(TAF=5K) and Sr2VP2O9(TAF=2.8K). Large negative shift of the 51V spectrum in comparison with Sr2VP2O9 is an evidence of a strong correlation (coupling) between all 51V nuclei mediated by electron system. 31P relaxation in Sr2VP2O9 exhibits 2 characteristic relaxation rates (R1short and R1long) with more than 3 orders difference between them. The R1long drastically decreases below 15K. R1short exceeds in two orders of magnitude the 51V relaxation rate in Sr2VP2O9, evidencing that P-ions are involved in magnetic hyperfine exchange process via the path V–O–P–O–V.