The crystal structure of π-ErBO3: New single-crystal data for an old problem

Pressure-supported crystal growth and single-crystal structure determination of Li2SiF6

“…This route led solely to a powder sample with low crystallinity, wherefore the structure determinations were merely performed on the basis of powder diffraction data. In 2005, Liivat et al [2] used Molecular Dynamics simulations to determine the correct space group (P321 or P 3m1) of Li 2 SiF 6 . The calculations led to the result that P321 is probably the correct space group.…”

“…In the case of powders with a low degree of crystallinity, high-pressure/high-temperature conditions can improve the size and the quality of the crystals. E.g., the use of high-pressure conditions led to the first crystalline tin borate β-SnB 4 O 7 [3], the new borates β-MB 2 O 5 (M = Hf, Zr) [4,5] and enabled the synthesis of single-crystals of π-ErBO 3 [6] with a high quality for a single-crystal structure determination. In this paper, we report the pressure-supported crystal growth of Li 2 SiF 6 in crystals with sufficient quality for single-crystal structure determination for the first time.…”

Спектральные и структурные характеристики ортоборатов Lu-=SUB=-1-x-y-=/SUB=-Ce-=SUB=-x-=/SUB=-Tb-=SUB=-y-=/SUB=-BO-=SUB=-3-=/SUB=-, полученных методом гидротермального синтеза

“…трудняет определение кристаллической структуры. Дей-ствительно, наблюдаемый набор дифракционных линий можно также описать моноклинной решеткой, которая изоструктурна описанной в работах [11][12][13], в предполо-жении, что уширение не позволяет разделить перекры-вающиеся близкие линии. Таким образом, сделать выбор между двумя близкими структурами не представляется возможным.…”

Ce2B8O15: High-pressure synthesis and crystal structure determination of a rare-earth polyborate exhibiting a new “Fundamental Building Block”

“…Their crystal structures are built up exclusively from triangular BO 3 groups except for p-CeBO 3 , which exhibits only BO 4 tetrahedra and was synthesized at elevated pressure of 2 GPa. Due to the fact that p-ErBO 3 crystallizes in the monoclinic pseudowollastonite-type structure, space group C2/c, exhibiting isolated three-membered rings of corner-sharing BO 4 tetrahedra, which are stacked in a shifted arrangement [12], we presume that pCeBO 3 exhibits the same isotypic structure. Crystals of the metaborate a-Ce(BO 2 ) 3 were synthesized by Goriounova et al in a covered platinum crucible at 1100 C by slow cooling to 900 C. It crystallizes in the monoclinic space group I2/a being a member of the isostructural series a-RE(BO 2 ) 3 (RE ¼ La--Nd, Sm--Tb) exhibiting corner-sharing BO 3 and BO 4 groups.…”