Structure and Characterization of K₂Na₃B₂P₃O₁₃, a New Nonlinear Optical Borophosphate with One-Dimensional Chain Structure and Short Ultraviolet Cutoff Edge

Abstract

Nonlinear optical (NLO) crystals, being the primary medium for laser wavelength conversion, are crucial in all-solid-state lasers. Borophosphates offer more structural varieties than pure borates and phosphates, and they have become popular as NLO crystal candidates. Through spontaneous crystallization, we acquired a noncentrosymmetric alkali metal borophosphate crystal material, K2Na3B2P3O13 (KNBPO). KNBPO crystallizes in the orthorhombic Cmc21 space group with the following unit cell parameters: a = 13.9238(18) Å, b = 6.7673(8) Å, c = 12.1298(15) Å, and Z = 4, and its structure is characterized by a fundamental building unit 1∞ [B2P3O13] chain structure made up of bridging oxygen linkages between BO4 and PO4 tetrahedra. KNBPO has a short ultraviolet (UV) cut-off edge (<186 nm), a congruent melting characteristic, good thermal stability, and a moderate second harmonic generation response roughly 0.42 times that of KH2PO4. Theoretical calculations reveal that the optical properties of the compound mainly originate from BO4 and PO4 units. Due to the short UV cut-off edge, KNBPO can be used as a potential NLO material in the UV and even deep UV regions, and it enhances the structural variety of borophosphates, which has a reference value for scholars investigating similar materials.

Sr14.06Gd14.63(BO3)24: A Gadolinium-Rich Borate with Magnetic Refrigeration Performance

“…The patterns of in-plane bending are distinguished by the peak at 586 cm –1 . The peaks observed in the infrared spectrum are well consistent with other [BO 3 ] 3– -containing compounds, − which further proves the correctness of Sr 14.06 Gd 14.63 (BO 3 ) 24 single-crystal structural information.…”

Improvement on Magnetocaloric Effect through Structural Evolution in Gadolinium Borate Halides Ba2Gd(BO3)2X (X = F, Cl)

“…At 250 nm, the reflectance reaches 70.45%, the cutoff edge of Ba 2 Gd­(BO 3 ) 2 F is lower than 250 nm. The experimental band gap value was estimated to be 5.88 eV according to the Tauc technique. , The good reflectance and the big band gap imply that Ba 2 Gd­(BO 3 ) 2 F has a possible application in the UV band. , …”

“…63,64 The good reflectance and the big band gap imply that Ba 2 Gd(BO 3 ) 2 F has a possible application in the UV band. 65,66 Electronic Structure Calculations. The calculated band structure of Ba 2 Gd(BO 3 ) 2 F is displayed in Figure S5a.…”

Na3[Al2B6P4O22(OH)3](H2O)6 and Na3[Al2BP2O11](H2O)0.5: Two Remarkable Complex Aluminum Borophosphates

“…In accordance with the detailed classification proposed by Kniep et al, , there are two different types of compounds containing both borates and phosphate groups but with distinct differences. Borophosphates have at least one BO 3 (or BO 4 ) group and one PO 4 tetrahedron share a bridged O atom, whereas the BO 3 /BO 4 and PO 4 anionic units are isolated from each other in the structure of borate phosphates. , …”

“…The structural chemistry of borophosphate/borate phosphate phases is very rich and complicated because of mixed anions of borates and phosphates, which possess open frameworks built from boron atoms as BO 4 tetrahedral or/and planar triangular BO 3 and phosphor atoms as PO 4 tetrahedral . Like borophosphate/borate phosphates, crystals with two mixed anions always have more abundant structural chemistry and physicochemical properties, such as borogermanates, borocarbonates, borosilicates, boroselenates, boronitrates, borosulfates, borotellurates, galloborates, aluminoborates, aluminophosphates, and so forth. ,− …”