Crystal structures and magnetic properties of two-dimensional antiferromagnets Co1− x Zn x TeMoO6

Abstract: Crystal structures and magnetic properties of metal telluromolybdates Co1− x Zn x TeMoO6 (x=0.0, 0.1,…,0.9) are reported. All the compounds have an orthorhombic structure with space group P21212 and a charge configuration of M2+Te4+Mo6+O6. In this structure, M ions form a pseudo-two-dimensional lattice in the ab plane. Their magnetic susceptibility measurements have been performed in the temperature range between 1.8 and 300K. The end member CoTeMoO6 shows a magnetic transition at 24.4K. The transition temperature for solid solutions rapidly decreases with increasing x and this transition disappears between x=0.4 and 0.5, which is corresponding to the percolation limit for the square-planer lattice. From the magnetization, specific heat, and powder neutron diffraction measurements, it is found that the magnetic transition observed in the CoTeMoO6 is a canted antiferromagnetic ordering of Co2+ ions. The antiferromagnetic component of the ordered magnetic moment (3.12(3)μ B at 10K) is along the b-axis. In addition, there exists a small ferromagnetic component (0.28(3)μ B) along the a-axis. [Copyright &y& Elsevier]