3d transition metal ions-based vanadates materials with layered crystal structures have triggered strong interest because of their various potential applications. For instance, nanostructured materials are promising candidates for photocatalysis [1], while crystalline microparticles are needed to study low-dimensional magnetism [2]. The crystal structure of BaCo3(VO4)2(OH)2 was resolved for the first time using small single crystals obtained by Dordevic et al. [3], and it can be described as brucite-like kagome sheets of Co3(OH)8 capped by VO4 tetrahedra and stacked along the c-axis. However, their physical or chemical properties were not investigated because no reported synthesis route was able to produce phase-pure BaCo3(VO4)2(OH)2.
Recently, phase-pure quasi-spherical nanoparticles with sizes in the range of 9-25 nm were obtained for the first time via a new synthetic route at ambient pressure [4]. Rietveld refinement of XRD patterns, vibrational spectroscopies, and high-resolution scanning transmission electron microscopy (HR-STEM) indicated that the rhombohedral crystal structure is not affected by nanostructuring. Magnetization measurements were consistent with high-spin Co2+ ions for which unquenched orbital angular momentum is present. Based on these results, we report another route for the synthesis of phase-pure micrometric-sized crystalline BaCo3(VO4)2(OH)2 which will allow a better understanding of the magnetic properties and particle-size effects [5]. The results of our structural and physicochemical characterizations will be presented.

References:

[1] M. Wang et al., Materials Letters, 2014, 122, 66-69.

[2] D. Boldrin et al., Phys. Rev. Lett., 2018, 121, 10, 107203.

[3] T. Đordevic et al., Acta Crystallogr. Section C: Cryst. Struct. Commun., 2013, 69, 2, 114-118.

[4] R. Dessapt et al., J. Mater. Chem. C, 2022, 10, 9, 3287-3291.

[5] B. Hadrane et al., Dalton Trans., 2023,52, 3501-3507.