NMR study of quasi-1D magnetic chain in cuprates LiCu2O2 and NaCu2O2

摘要

NMR investigation of magnetic structure and phase transitions in two isostructural quasi-one-dimensional cuprates LiCu2O2 and NaCu2O2 has been performed. While LiCu2O2 exhibits a magnetic phase transition at Tc = 24 K, NaCu2O2 orders magnetically at around 13 K. 6,7Li and 23Na NMR spectra in LiCu2O2 and NaCu2O2, respectively, provide an unambiguous experimental evidence that below Tc an incommensurate in-chain helical spin structure is established in both compounds. However, the features of the observed low temperature NMR are different pointing to different properties of the helical magnetic structure.