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

TL;DR

This study investigates how doping with Co and Zn affects the magnetic properties of a honeycomb-lattice compound, revealing the suppression or emergence of magnetic order and the potential realization of a spin liquid state.

Contribution

It provides experimental insights into how magnetic and nonmagnetic dopants influence spin liquid behavior in a honeycomb lattice, highlighting the transition to antiferromagnetic order or suppression of spin liquid states.

Findings

Co doping induces antiferromagnetic long-range order.

Zn doping weakens magnetic frustration and suppresses spin liquid behavior.

Low-temperature specific heat and susceptibility suggest a spin liquid candidate.

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.