3D architectures of iron molybdate: Phase selective synthesis, growth mechanism, and magnetic properties

摘要

Monoclinic and orthorhombic Fe,(MoO4)(3) microsized particles with complex 3D architectures have been selectively prepared by a template-free hydrothermal process. The pH value, reaction time, temperature, and molybdenian source have crucial influence on the phase formation, shape evolution, and microstructures. Monoclinic Fe-2(MoO4)(3) particles obtained at pH I and pH 1.65 display ferromagnetic ordering at 10.4 K and 10.5 K, respectively, and the ferromagnetic component is determined to be 0.0458 mu(B) and 0.0349 mu(B), per Fe-ion at 10 K, respectively. For orthorhombic beta-Fe-2(MoO4)(3), antiferromagnetic ordering. was observed about 12 K. At higher temperatures, beta-Fe-2(MoO4)(3) began to follow the Curie-Weiss law with theta = -70 K. Such 3D architectures of monoclinic and orthorhombic beta-Fe-2(MoO4)(3) microparticles with unique shapes and structural characteristics may find applications as catalysts and as well as in other fields.