High-pressure/high-temperature synthesis of Ln${}_2$CdB${}_5$O${}_{11}$(OH) (Ln = Tm, Lu)

This report presents work on the orthorhombic phases Ln${}_2$CdB${}_5$O${}_{11}$(OH) (Ln = Tm, Lu). The title compounds were synthesized in a Walker-type multianvil device at 7 GPa and 650 °C, and the resulting samples were thoroughly investigated through single-crystal and powder X-ray diffraction methods. Lu${}_2$CdB${}_5$O${}_{11}$(OH) crystallizes in the space group Pmna (no. 53) with the unit cell parameters a = 12.772(2), b = 4.6017(7), and c = 12.481(2) Å. Similar unit cell parameters are observed for the isotypic Tm analogue compound. The crystals have a layered crystal structure built up by four-, five-, and eight-membered rings of corner-sharing [BO${}_4$] tetrahedra. The structural data are accompanied by attenuated total reflection (ATR) infrared spectra and energy-dispersive X-ray spectroscopy (EDX).