High-Temperature, High-Pressure Hydrothermal Synthesis and Characterization of an Acentric Borate Fluoride: Ba₂B₅O₉F·0.5H₂O

Abstract

A new borate fluoride, BaBOF·0.5HO, has been synthesized by high-temperature, high-pressure hydrothermal method, characterized by a combination of techniques and its structure determined by single-crystal X-ray diffraction. The compound crystallizes in the noncentrosymmetric space group P4̅ n2 (No. 118) and powder SHG measurements were performed to confirm the absence of a center of symmetry. Its crystal structure is formed of a new fundamental building block which shares oxygen atoms with neighboring blocks to form a 3D borate framework with 12- and 8-ring channels where the Ba cations, F anions, and water molecules are located. The structure is compared with those of minerals and synthetic borate fluoride and chlorides with similar framework compositions. The B MAS NMR experimental results are in accord with those from crystal structure analysis and the resonances in the spectrum are assigned. The presence of water was confirmed by IR spectroscopy, and its content and the thermal decomposition products were determined by thermogravimetric analysis and powder X-ray diffraction.

Designing Sulfide Borate as a Novel Type of Second-Order Nonlinear-Optical Material

“…Combining these situations, we have a strong interest in developing sulfide borate-type NLO materials that can hybridize the advantages of chalcogenides’ large NLO second-order susceptibilities and borates’ rich acentric building units and large LIDTs. Keeping this in mind, a family of pentaborates attracted our attention, namely, M II 2 B 5 O 9 X (M II = Ca, Sr, Ba, Eu, Pb; X = F, Cl, Br, I, OH). − Interestingly, all of them crystallize in the NCS orthorhombic space group Pnn 2, and several demonstrate good NLO properties. − It is well-known that divalent alkaline-earth cations can be replaced with Eu 2+ cations in most cases in view of their similar ionic radii and coordination preferences. Meanwhile, when monovalent X – anions are replaced with divalent S 2– ones, one of the two M II cation sites can be occupied by a Eu 3+ ion; in that sense, a sulfide borate, Eu 2 B 5 O 9 S (EBOS), was designed and subsequently synthesized (Figure a).…”

A Review What Is Hydrothermal ?

“…Penelitian ini bertujuan untuk mengetahui bagaimana proses pembentukan material dengan menggunakan metode hydrothermal (28; 29). Air karena gaya gravitasi selalu mempunyai kecenderungan untuk bergerak ke bawah, akan tetapi apabila air tersebut kontak dengan suatu sumber panas maka akan terjadi perpindahan panas sehingga temperatur air menjadi lebih tinggi dan air menjadi lebih ringan (30)(31)(32)(33)(34)(35)(36)(37). Keadaan ini menyebabkan air yang lebih panas bergerak ke atas dan air yang lebih dingin bergerak turun ke bawah (38)(39)(40)(41)(42)(43), sehingga terjadi sirkulasi air atau arus konveksi (44)(45)(46).…”

Strong green upconversion emission from submicron spindle-shaped SrMoO4:Yb3+,Er3+

“…The HT method could serve as one of the most appropriate routes for lanthanide doped SrMoO 4 materials due to the incorporation of pressure along with a relatively low temperature and short reaction time. [26][27][28][29] It is a common approach to synthesize functional materials with a desirable and controllable size and morphology. Generally, this process involves specific temperatures and pressures where the solvent inside a reaction vessel reaches its critical or supercritical state to produce nanostructures.…”