Growth, crystal structure and optical properties of layered dibarium cadmium diborate, Ba2Cd(BO3)2

A novel dibarium cadmium diborate, Ba2Cd(BO3)2, has been successfully synthesized by standard solid-state reaction. Large sheet-like crystal with size up to 20 mm × 15 mm × 0.7 mm has been obtained using top-seed solution growth method. Ba2Cd(BO3)2 crystallizes in the monoclinic space group C2/m with a = 9.6305(4) Å, b = 5.3626(3) Å, c = 6.5236(2) Å, β = 118.079(3)°, Z = 2. The crystal structure is composed of isolated [BO3] triangles, [CdO6] octahedra and [BaO9] polyhedra. CdO6 are vertex-connected with six BO3 to form infinite ∞[Cd(BO3)2] layers extending in (0 0 1) plane, and two rows of Ba atoms closely occupy two side of ∞[Cd(BO3)2] layers to forming stoichiometric sheets. IR and transmittance spectrum of Ba2Cd(BO3)2 were reported.

A new phase, Ba2Cd(BO3)2, has been discovered in the ternary M2O–CdO–B2O3 (M = alkaline-earth metal) system. The crystal structure is built up from the stacking of infinite stoichiometric layers along the c axis.Figure optionsDownload as PowerPoint slideHighlights
► Ba2Cd(BO3)2 is the first borate discovered in the ternary M2O–CdO–B2O3 (M = alkaline-earth metal) system.
► Ba2Cd(BO3)2 crystal structure includes a two-dimensional infinite stoichiometric layers.
► Intrinsic layered structure leads to layered crystal morphology in the process of crystal growth.