Crystal structure and anisotropic magnetic properties of CaCo4(TeO3)4Cl2

We report on the discovery and the magnetic properties of CaCo4(TeO3)(4)Cl-2 Single-crystal X-ray diffraction shows that this compound crystallizes on a monoclimc lattice, in the space group C2/c with a = 19.869(1) A, b = 5.323(1) A, c = 16.965(1) A and beta = 125.091(1)degrees. The compound has a layered structure that additionally exhibits ID structural motifs composed of staircase-like double chains of magnetic face- and corner-sharing [CoO5Cl] and [CoO6] octahedra, which are linked by Ca2+ ions and [TeO3](2-) units. Temperature-dependent magnetic measurements reveal antiferromagnetic (AFM) ordering with a Neel temperature of T-N approximate to 11.5 K and an effective moment of mu(eff) approximate to 5.2 mu(B)/Co consistent with expectations for Co2+ high spin. The Curie-Weiss temperature theta approximate to -42.1 K indicates AFM interactions dominate between the magnetic moments. The magnetic ordering transition in the zero-field heat capacity shows a lambda-type anomaly. Direction-dependent magnetic measurements on single-crystals reveal an anisotropic character of the magnetization. For H ? c corresponding to a direction within the layers and perpendicular to the double chains the AFM transition temperature is suppressed in magnetic fields higher than similar to 7.9 T and a clearly pronounced metamagnetic phase transition is observed.