Discovery of First Magnesium Fluorooxoborate with Stable Fluorine Terminated Framework for Deep‐UV Nonlinear Optical Application

Abstract

The generated light can be tuned to cover almost the entire spectral range from deep‐ultraviolet to terahertz wavelengths by utilizing the nonlinear optical crystals with a simple frequency doubling process. Among them, the discovery of novel candidates for the production of deep‐ultraviolet light is by extension a great challenge toward realizing the vast potential. Actually, the availability for this process mainly depends on whether the critical performance can be well coexisted in one practical crystal. Herein, the first magnesium fluorooxoborate MgB5O7F3 was synthesized as a new competitive candidate for deep‐ultraviolet nonlinear optical application. It has a sufficiently large nonlinearity and a deep‐ultraviolet phase matching wavelength, indicating that it holds great potential for the production of coherent light below 200 nm. The critical performance enhancement of MgB5O7F3 when compared with its isomorphic phases was demonstrated and discussed. More importantly, we proposed that fluorooxoborate system with the general formula of MB5O7F3 (M=divalent metal) possesses stable fluorine terminated framework, which makes them tend to retain their crystallized space groups unchanged.

Ba10LuB18O32F13: the first example of borate in the Lu–B–O–F system with the unprecedented FBB [B9O22]

“…To date, in addition to the most commonly used NLO crystals, such as KBe 2 BO 3 F 2 15 (KBBF), etc., a series of borates containing [BOxF 4−x ] units with excellent optical properties has been reported. For example, the AB 4 O 6 F (A = NH 4 , Na, Cs) [16][17][18] and AEB 5 O 7 F 3 (AE = Mg, Ca, Sr) [19][20][21] series and BaB 4 O 6 F 2 22 all have cut-off edges below 200 nm.…”

Finding a Series of BaBOF3 Fluorooxoborate Polymorphs with Tunable Symmetries: A Simple but Flexible Case

“…and properties (kinetic effect, linear, nonlinear optical, etc.) were well regulated. − In the past few years, studies have shown that the introduction of F in borates to form fluorooxoborates can largely enrich the structural chemistry of the borate family and also accelerate the discovery of new optical materials with target properties. − Structurally, the introduction of F in a regular [BO 4 ] tetrahedron to form a [BO 3 F] unit can reduce the microscopic symmetry and make the anionic framework more flexible, which might help us obtain more polymorphs with the assigned molecular formula . It should be noted that the B–O/F anionic frameworks of AB 4 O 6 F (A = NH 4 , Na, Rb, Cs) − and MB 2 O 3 F 2 (M = Pb, Sn, Ba) − are very flexible, and the arrangement and symmetry are heavily affected by A-and M-site cations, making them crystallize in the different noncentrosymmetric space group, indicating that fluorooxoborates might have more flexible structures when compared with pure borates without B–F bonds.…”

KPb3(o-C5H4NCOO)2Cl5: a brand-new stable lead chloride with good comprehensive nonlinear optical performance

“…[1][2][3][4] Actuated by the rapid development of advanced technology, NLO crystals have significant applications in all-solid-lasers, laser guidance, precise micro-manufacturing, biological tissue imaging and advanced scientific instruments. [5][6][7][8][9][10][11] Over the past decades, scientists have made great efforts to explore NLO crystals and elucidate the relationship between their structures and NLO properties. Consequently, some famous NLO crystals, like β-BaB 2 O 4 (BBO), LiB 3 O 5 (LBO), KBe 2 BO 3 F 2 (KBBF), KH 2 PO 4 (KDP), KTiOPO 4 (KTP) and AgGaS 2 , have been commercialized.…”