M3(TeO3)(SO4)(OH)2·2H2O (M = Ni, Co): Two Novel Quasi-2D Layered Tellurite-Sulfate Compounds with a Distorted Striped Kagomé Lattice

Two novel transition-metal-based tellurite-sulfate compounds M3(TeO3)­(SO4)­(OH)2·2H2O (M = Ni, Co) have been successfully obtained through a conventional hydrothermal method. The titled compounds feature a quasi-2D layer structure with a distorted striped kagomé lattice constructed by magnetic M2+ ions. We note that such spin lattice of the titled compounds is strongly related to the staircase kagomé lattice seen in M3V2O8 (M = Ni, Co). Our results combined from magnetic susceptibility and magnetization measurements suggest that Ni3(TeO3)­(SO4)­(OH)2·2H2O displays a spin-canted antiferromagnetic behavior with a Néel temperature of ∼21 K.