To improve the key properties of nonlinear optical crystals assembled with tetrahedral functional building units

Abstract

We report a new nonlinear optical crystal assembled exclusively with tetrahedral functional building units in which enhanced birefringence (Δn) and second-harmonic generation (deff) were observed.

Tetrafluoroborate-Monofluorophosphate (NH4)3[PO3F][BF4]: First Member of Oxyfluoride with B–F and P–F Bonds

“…It should be noted that all the [PO 3 F] and [BF 4 ] units are in an isolated configuration without any connection and thus (NH 4 ) 3 [PO 3 F]­[BF 4 ] can be classified as fluoroborate-fluorophosphates, which is the first case in this family. The P–O, P–F, and B–F bond lengths are in the region of 1.471–1.478, 1.590, and 1.385–1.396 Å, respectively, which show a good match with other reported fluorooxoborates and fluorophosphates. − The reasonable bond lengths also give the acceptable bond valence sum calculations and oxidation states of related atoms (Table S2 in the SI). The hydrogen bonds from [NH 4 ] units in (NH 4 ) 3 [PO 3 F]­[BF 4 ] link the whole structure, that is N–H···O bonds for [PO 3 F] and N–H···F bonds for [BF 4 ] units, respectively.…”

“…Oxyfluoride (or oxide-fluoride) is an important branch of mixed anion compounds, and therefore, considerable efforts have been made to find new oxyfluorides and also to understand the crucial roles of multiple anions on property modification. ,, In recent years, oxyfluorides with different types of fluorinated [MO m – n F n ] (M = B, P, S, Si; m = 4, 6; n = 1–3, etc.) units have been designed using the strategy of fluorine introduction in oxides, which has expanded the solid-state chemistry with newly developed branches and systems like fluorooxoborates, − fluorophosphates, , fluorooxosilicates, , and fluorooxosulfates. , The fluorinated units in these oxyfluorides have an indispensable role for the improved symmetry, enlarged energy gap, and enhanced polarizability anisotropy, which can be regarded as new optical-active units for regulating the microstructures and optical properties. Fluorooxoborates tend to form layered configurations, which can be verified by the increased proportion of fluorooxoborates in two-dimensional layered structures (53.33%) when compared with borates (10.26%) without fluorinated [BO 4– n F n ] ( n = 1–3) units .…”

Polymorphism, polytypism and modular aspect of compounds with the general formula A 2 M 3(TO4)4 (A = Na, Rb, Cs, Ca; M = Mg, Mn, Fe3+, Cu2+; T = S6+, P5+): order–disorder, topological description and DFT calculations

“…Alkaline sulfates and phosphates of alkaline-earth and transition elements attract interest because of electrochemical properties and their application as electrode materials for lithium-and sodium-ion batteries (Hwang et al, 2017;Reynaud et al, 2014;Masquelier & Croguennec, 2013). Moreover, these compounds are also characterized by the luminescent (Sinusaite et al, 2021;Majgier et al, 2021;Nan et al, 2020) and nonlinear optical (Xu et al, 2021;Rajeswari et al, 2018;Joice Malini et al, 2021;Dang et al, 2021;Bai et al, 2021;Marimuthu & Perumal, 2021), magnetic (Kovrugin et al, 2019;Li et al, 2020;Bolotina et al, 2019;Benhsina et al, 2021;Maspoch et al, 2007) and catalytical (Moffat, 1978) properties.…”

Linear and Nonlinear Optical Properties of Centrosymmetric Sb4O5SO4 and Noncentrosymmetric Sb4O4(SO4)(OH)2 Induced by Lone Pair Stereoactivity

“…Lasers with different wavelengths are widely applied in both civil and military fields, such as precision manufacturing, laser medicine, remote communication, optoelectronic devices, and so forth. − Nonlinear optical (NLO) materials can achieve the tunable laser output by frequency conversion and are of great interest for scientists. − Over the past few decades, some commercial NLO crystals, such as AgGaX 2 (X = S, Se), , ZnGeP 2 , KTiOPO 4 , KH 2 PO 4 , β-BaB 2 O 4 , LiB 3 O 5 , have been developed. However, with the development of technologies, these crystals cannot satisfy the increasing requirements of frequency conversations in the whole wavelength region.…”