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arXiv · 1210.0272

51V-NMR study of antiferromagnetic state and spin dynamics in the quasi-one-dimensional BaCo2V2O8

Yukiichi Ideta·Yu Kawasaki·Yutaka Kishimoto·Takashi Ohno·Yoshitaka Michihiro·Zhangzhen He·Yutaka Ueda·Mitsuru Itoh
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Abstract

We report on our 51V-NMR study of static and dynamical magnetic properties in the quasi-one-dimensional antiferromagnet BaCo2V2O8. Although the NMR spectrum shows well-defined antiferromagnetic (AF) order in the N\'eel 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 Co2+ 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 Co2+ ions. The linear relation between the nuclear spin-lattice relaxation rate 1/T1T and the magnetic susceptibility chi indicates that the Q component of magnetic susceptibility chi(Q) is roughly proportional to chi, where Q is the AF wave number. A change in slope of 1/T1T with respect to \chi around 150 K suggests a change in the AF spin fluctuation spectrum.

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Yukiichi Ideta, Yu Kawasaki, Yutaka Kishimoto, Takashi Ohno, Yoshitaka Michihiro, Zhangzhen He, Yutaka Ueda, Mitsuru Itoh. 2012-10-01. 51V-NMR study of antiferromagnetic state and spin dynamics in the quasi-one-dimensional BaCo2V2O8. https://doi.org/10.1103/physrevb.86.094433

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