Nantes Université, CNRS, Institut des Matériaux de Nantes Jean Rouxel, IMN, F-44000 Nantes, France.
Dalton Trans. 2023 Mar 14;52(11):3501-3507. doi: 10.1039/d2dt04110c.
Microplatelets of the layered-kagome compound BaCo(VO)(OH), which is the Co analogue of mineral vesignieite BaCu(VO)(OH), have been prepared with very high yield by hydrothermal reaction using synthetic karpenkoite CoVO(OH)·2HO as starting reagent. The Rietveld refinement of X-ray diffraction data indicates that CoVO(OH)·2HO is isostructural with martyite ZnVO(OH)·2HO. Two single-phased samples of microstructured BaCo(VO)(OH) have been characterized using powder X-ray diffraction, FT-IR and Raman spectroscopies, thermal analyses, scanning electron microscopy, energy-dispersive X-ray spectroscopy and magnetisation measurements. Their crystallite sizes perpendicular to the -axis are in the range of 92(3) to 146(6) nm and depend on the synthesis conditions. Results have been compared to those previously obtained for quasi-spherical nanoparticles having a crystallite size of the order of 20 nm, to explore the effect of the crystallite size on the properties of BaCo(VO)(OH). This study highlights that the magnetic properties depend on the crystallite sizes only at low temperatures.
层状 Kagome 化合物 BaCo(VO)(OH)的微板，是矿物 vesignieite BaCu(VO)(OH)的 Co 同系物，通过使用合成的卡本考石 CoVO(OH)·2HO 作为起始试剂的水热反应，以非常高的产率制备。X 射线衍射数据的 Rietveld 精修表明，CoVO(OH)·2HO 与 martyite ZnVO(OH)·2HO 具有同构性。使用粉末 X 射线衍射、FT-IR 和拉曼光谱、热分析、扫描电子显微镜、能量色散 X 射线光谱和磁化率测量对具有微结构的 BaCo(VO)(OH)的两个单相样品进行了表征。它们沿 - 轴的晶粒度在 92(3)到 146(6)nm 范围内，取决于合成条件。结果与先前获得的具有约 20nm 晶粒度的准球形纳米粒子的结果进行了比较，以探索晶粒度对 BaCo(VO)(OH)性质的影响。这项研究表明，仅在低温下，磁性性质才取决于晶粒度。
