Magnetic properties of the BaNi₂(As_1-xV_x)₂O₈ honeycomb system

The Kitaev model for magnetic interactions on a honeycomb lattice, which underlies the exotic quantum spin liquid (QSL) state in such systems, has long been established and experimentally confirmed. Current studies on Kitaev QSLs have focused on heavy-metal-based Mott insulators where strong spin-orbit coupling (SOC) leads to bond-dependent spin anisotropy. Here we examine a 3d transition-metal-based honeycomb lattice material BaNi₂(As_1-xV_x)₂O₈, where the SOC is weak but spin exchange coupling is strongly frustrated due to the crystal field. We present an investigation of the crystal structure and magnetization of this series of Ni-based honeycomb materials, providing an alternative perspective in the search for the QSL in 3d-element-based honeycomb systems.