Synthesis, structure and magnetic properties of ACo5(SeO3)4(OH)2F (A = Rb, Cs): the first compounds with a distorted 2-uniform lattice (T29)

Based on the crystal structure of A2Cu5(TeO3)(SO4)3(OH)4 (A = Na, K), two new compounds ACo5(SeO3)4(OH)2F (A = Rb, Cs) have been synthesized by introducing F− ions, achieving the extension from a one-dimensional kagomé strip lattice to a distorted 2-uniform lattice (T29). Magnetic measurements indicate that RbCo5 exhibits antiferromagnetic order at low temperatures, while CsCo5 shows canted antiferromagnetic behavior. Both compounds display a field-induced magnetic transition at their respective critical fields. To the best of our knowledge, this is the first reported synthesis of compounds with a distorted 2-uniform lattice (T29).