Nuclear Magnetic Resonances and Long-Range Superexchange Interactions via Cu-O-V-O-Cu Linkages in LiCuVO₄

NMR study of lineshifts and relaxation rates of the one-dimensional antiferromagnetLiCuVO4

“…This broadening is attributed to an evolving distribution of hyperfine fields at the nuclear sites approaching the transition into a long-range-ordered state of the electronic system at a T N = 1.3 K. 16,18,20 Figure 2͑A͒ and 2͑B͒ show the shift of the 7 Li line for the orientation H ʈ b and H Ќ b, respectively. For both orientations the lineshift K͑T͒ nicely follows the Bonner-Fisher-type behavior 29 for the bulk susceptibility bulk ͑T͒ of an antiferromagnetic spin chain as indicated by the solid line.…”

“…A broad range of properties of polycrystalline LiCuVO 4 have been studied such as structure, 9,10 susceptibility, 11,12 specific heat, 13,14 electrochemical properties, 15 and properties using resonance methods such as NMR and EPR. [16][17][18][19][20] This material gained some interest for its prospective use in rechargeable batteries 15 which are considered important for various applications. As single-crystalline material became available, 21 its properties have been studied by investigating the temperature T dependence of the magnetic susceptibility ͑T͒, magnetic structure in the ordered state using neutron diffraction 22 in combination with band-structure calculations, 23 EPR, 17 heat transport, and thermal conductivity 24,25 as well as lattice dynamics by infrared spectroscopy.…”

NMR studies of incommensurate quantum antiferromagnetic state of LiCuVO4

“…The structure of LiCuVO 4 [1,2] is characterized by chains of edge-coupled LiO 6 and CuO 6 octahedra running along the a-and b-crystal axes, respectively, and thus consists of alternating packed layers containing arrays of Li + or Cu 2+ chains. Within the planes, neighbouring Cu chains are connected with each other by VO 4 tetrahedra that alternate up and down along the chain direction and form Cu-O-V-O-Cu superexchange bonds.…”

Short-Range and Long-Range Order in AFM–FM Exchange Coupled Compound LiCu2(VO4)(OH)2

“…Our attempt to simulate the observed 7 Li NMR spectra by a quadrupole triplet gives the quadrupole frequency of 7 Li nuclei of about 1.7 MHz, which is unlikely because it is at least 1 order of magnitude higher than typical values of 7 Li quadrupole frequencies in lithium cuprates. For example, ν Q (Li) = 51.7 kHz in LiCu 2 O 2 , 45 kHz in La 2 Cu 0.5 Li 0.5 O 4 , and 48 kHz or 42 kHz in LiCuVO 4 , more than 30 times less than 1.7 MHz. Moreover, no traces of visible quadrupole effects were found in the room-temperature 7 Li spectrum of LiCu 2 (VO 4 )­(OH) 2 presented in the upper inset to Figure .…”