Magnetic properties of the doped spin-i honeycomb-lattice compound In_3Cu_2VO_9

摘要

We report magnetic properties in the Co- and Zn-doped spin-1/2 honeycomb-lattice compound In_3Cu_2VO_9. Magnetic susceptibility and specific heat experiments show no long-range ordering down to 2 K in In_3Cu2VO_9. Analyses of electronic structures and states suggest that the ground state of undoped In_3Cu_2VO_9 is probably a Néel antiferromagnet (AFM). When Cu~(2+) ions are partially substituted by Co~(2+) ions, both the impurity potential scattering and magnetic scattering induced by the magnetic Co~(2+) ions enhance the three-dimensional character of the magnetic coupling and lead to an AFM long-range order. Replacement of Cu~(2+) with nonmagnetic Zn~(2+) ions weakens the AFM correlation between Cu~(2+) ions, leading to suppression of the AFM state.