Magnetic properties in the doped spin-1/2 honeycomb-lattice compound In${}_3$Cu${}_2$VO${}_9$

Abstract

We report the magnetic properties in the Co- and Zn-doped spin-1/2 honeycomb-lattice compound In${}_3$Cu${}_2$VO${}_9$. The magnetic susceptibility and specific heat experiments show no long-range ordering down to 2 K in In${}_3$Cu${}_2$VO${}_9$. In the low temperature range, approximately T${}^2$-dependent magnetic specific heat and linearly T-dependent spin susceptibility were observed, suggesting a spin liquid candidate with a S = 1/2 honeycomb lattice. When Cu${}^{2+}$ ions are partially substituted by Co${}^{2+}$ ions, both impurity potential scattering and magnetic impurity scattering induced by magnetic Co${}^{2+}$ ions break the homogenous spin-singlet spin liquid state, and lead to an antiferromagnetic(AFM) long-range correlation. While replacing Cu${}^{2+}$ with nonmagnetic Zn${}^{2+}$ ions, the frustration and antiferromagnetic correlation between Cu${}^{2+}$ ions is weakened, leading to breakage of a spin liquid state and suppression of the low-dimensional AFM.

6 pages, 5 figures