Hydrothermal Synthesis and Magnetic Characterization of the Quaternary Oxide CoMo2Sb2O10

The new quaternary layered oxide CoMo2Sb2O10 was synthesized by hydrothermal synthesis techniques, and its structure was determined from single-crystal X-ray diffraction data. CoMo2Sb2O10 crystallizes in the monoclinic space group C2/c with one Sb3+, Mo6+, and Co2+ atom site per unit cell, respectively. The crystal structure contains building units consisting of [Co2O8]n, [Mo2O8]n, and [SbO2]n chains. These are connected through corner sharing to form charge-neutral [CoMo2Sb2O10]n layers. Thermal decomposition of CoMo2Sb2O10 starts at 550 °C. The magnetic susceptibility follows a Curie–Weiss law above 50 K with a Curie constant of C = 3.46 emu·K·mol–1 corresponding to an effective moment of μeff = 5.26 μB per cobalt atom and a Curie–Weiss temperature θ = −13.2 K. Short-range anti-ferromagnetic ordering dominates below 5 K. Magnetic susceptibility and heat capacity data can be successfully modeled by the predictions from an Ising linear chain with an intrachain spin exchange of ca. −7.8 K.