K₉[B₄O₅(OH)₄]₃(CO₃)X·7H₂O (X = Cl, Br): Syntheses, Characterizations, and Theoretical Studies of Noncentrosymmetric Halogen Borate–Carbonates with Short UV Cutoff Edges

Abstract

Two mixed halogen borate–carbonates K9[B4O5(OH)4]3(CO3)­X·7H2O (X = Cl, Br) have been successfully synthesized with the hydrothermal method. They crystallize in the space group P6̅2c, and their structures feature 3D networks consisting of the K9O30Cl polyhedra. The isolated [B4O9]6– groups and [BO3]3– triangles are filled in the space of 3D networks. K9[B4O5(OH)4]3(CO3)­X·7H2O (X = Cl, Br) show the largest band gaps (6.34 and 5.65 eV, respectively) among the borate–carbonate systems. In addition, we investigated the main-group-element borate halides based on the Inorganic Crystal Structure Database, compared the structures, and summarized which structures are beneficial to the formation of isomorphic compounds. Herein, the syntheses, structures, first-principle calculations, and optical properties were reported in the work.

NaRb3B6O9(OH)3(HCO3): A Borate-Bicarbonate Nonlinear Optical Material

“…28 Another barium borate carbonate chloride, Ba 2 (BO 3 ) 1−x (CO 3 ) x Cl 1+x (0 < x < 0.5), was obtained by the high temperature method, 30 while two potassium borate carbonate halides, K 9 [B 4 O 5 (OH) 4 ] 3 (CO 3 )X• 7H 2 O (X = Cl, Br), were synthesized by hydrothermal method. 31 We report the first synthetic borate−bicarbonate NLO compound, NaRb 3 B 6 O 9 (OH) 3 (HCO 3 ) (SRBOC). A single crystal of the compound was grown by the solvothermal method.…”

“…Two barium borate carbonates, Ba 3 [B 6 O 10 (OH) 2 ]­(CO 3 ) and Ba 6 [B 12 O 21 (OH) 2 ]­(CO 3 ) 2 , were synthesized by the high-temperature, high-pressure hydrothermal method (460 °C and 600 bar) . Another barium borate carbonate chloride, Ba 2 (BO 3 ) 1– x (CO 3 ) x Cl 1+ x (0 < x < 0.5), was obtained by the high temperature method, while two potassium borate carbonate halides, K 9 [B 4 O 5 (OH) 4 ] 3 (CO 3 )­X·7H 2 O (X = Cl, Br), were synthesized by hydrothermal method …”

Spectrally uncorrelated biphotons generated from “the family of BBO crystal”

“…Designing new borate crystals with novel characteristics (eg, higher nonlinear coefficient, smaller walk-off effect, better wavelength range) is still an active research area in the study of nonlinear optical crystals. [76][77][78] For example, following the anionic group theory, new nonlinear optical materials can be designed through the combination of borate and other material genomes. 77,78 In the future, more and more borate crystals might be synthesized.…”

“…[76][77][78] For example, following the anionic group theory, new nonlinear optical materials can be designed through the combination of borate and other material genomes. 77,78 In the future, more and more borate crystals might be synthesized. Therefore, it is also possible to design and discover more borate crystals to prepare spectrally pure single-photon sources.…”

Spectrally uncorrelated biphotons generated from `the family of BBO crystal'

“…Designing new borate crystals with novel characteristics (e.g., higher nonlinear coefficient, smaller walk-off effect, better wavelength range) is still an active research area in the study of nonlinear optical crystals [69][70][71]. For example, following the anionic group theory, new nonlinear optical materials can be designed through the combination of borate and other material genomes [70,71]. In the future, more and more borate crystals might be synthesized.…”