NMR study of the paramagnetic state of low-dimensional magnets LiCu 2 O 2 and NaCu 2 O 2

A comprehensive NMR study of the magnetic properties of single crystal LiCu 2 O 2 (LCO) and NaCu 2 O 2 (NCO) is carried out in the paramagnetic region of the compounds for various orientations of single crystals in an external magnetic field. The values of the electric-field gradient (EFG) tensor, as well as the dipole and transferred hyperfine magnetic fields for 63,65 Cu, 7 Li, and 23 Na nuclei are determined. The results are compared with the data obtained in previous NMR studies of the magnetically ordered state of LCO/NCO cuprates.