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arXiv:1210.0272v1 [cond-mat.str-el] We report on our 51 V-NMR study of static and dynamical magnetic properties in the quasione-dimensional antiferromagnet BaCo2V2O8. Although the NMR spectrum shows well-defined antiferromagnetic (AF) order in the Néel ground state, the AF characteristic from the NMR spectrum is incomplete between 3.5 K and TN = 5.4 K, which could be affected by quantum spin fluctuations. The AF NMR spectrum indicates two V sites experiencing different magnetic field magnitudes, HA1 = 2.1 kOe and HA2 = 3.8 kOe. These internal fields could be explained by accounting for the classical and the pseudo-dipolar fields from Co 2+ spins with a proposed magnetic structure based on the neutron diffraction measurements. In the paramagnetic state, the nuclear spin relaxation is dominated by AF spin fluctuations through the dipolar-type coupling between V and surrounding Co 2+ ions. The linear relation between the nuclear spin-lattice relaxation rate 1/T1T and the magnetic susceptibility χ indicates that the Q component of magnetic susceptibility χ(Q) is roughly proportional to χ, where Q is the AF wave number. A change in slope of 1/T1T with respect to χ around 150 K suggests a change in the AF spin fluctuation spectrum.

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