Nanocrystalline BaCo3(VO4)2(OH)2 with a kagome lattice of Co(ii) ions: synthesis, crystal structure and magnetic properties

We report an initial magnetic study of highly crystalline nanoparticles of the layered-kagome compound BaCo3(VO4)(2)(OH)(2). Quasi-spherical nanoparticles with size in the range of 9-25 nm were elaborated for the first time via a new synthetic route at ambient pressure. Rietveld refinement of X-ray diffraction data, vibrational spectroscopies and high-resolution scanning transmission electron microscopy indicates that the rhombohedral crystal structure of BaCo3(VO4)(2)(OH)(2) is not modified by nanostructuring. Magnetisation measurements are consistent with high-spin Co2+ ions for which unquenched orbital angular momentum is present. Temperature-dependent magnetic susceptibility shows no apparent magnetic ordering or spin freezing down to 2 K and suggests finite-size or surface effects at low temperatures.

Automated summary

A new synthetic route was used to successfully produce highly crystalline nanoparticles of BaCo3(VO4)(2)(OH)(2). The magnetic study revealed that the crystal structure remained unchanged and the Co2+ ions exhibited high-spin with unquenched orbital angular momentum. The absence of magnetic ordering or spin freezing at low temperatures suggests the presence of finite-size or surface effects.