An Unprecedented Antimony(III) Borate with Strong Linear and Nonlinear Optical Responses

Abstract

Antimony(III) borates with a stereochemical active lone pair remained unknown, although the first antimony borate was reported more than twenty years ago. Now, the first antimony(III) borate in a closed system is successfully synthesized, namely SbB3O6. Remarkably, SbB3O6 not only exhibits an exceptional linear optical response, that is, birefringence of Δn=0.290 at the wavelength of 546 nm, which is the largest among borates, but also has a strong nonlinear optical response of 3.5 times larger than the benchmark KH2PO4, exceeding those of most borates. Theoretical calculations reveal that the coexistence of strong linear and nonlinear optical responses in SbB3O6 should be attributable to the synergistic effect of π‐conjugated B−O anionic groups and Sb3+ with stereochemically active lone pair. This work provides a new class of optical bi‐functional materials with potential prospects in integrated optical devices.

Sn2B5O9Br as an Outstanding Bifunctional Material with Strong Second‐Harmonic Generation Effect and Large Birefringence

“…The brilliant birefringence of SBOB is almost larger than those of the reported excellent borate birefringent crystals at 546 nm such as α‐BaB 2 O 4 (0.122 at 546 nm), [ 8 ] Ca(BO 2 ) 2 (0.136 at 546 nm), [ 10 ] BiB 3 O 6 (0.174 at 546 nm), [ 11 ] and even SbB 3 O 6 (0.290 at 546 nm). [ 12 ]…”

“…For the crystals with stereochemical activity lone pair (SCALP) cations, except for the anion groups, the SCALP cations also have great effect on their enhanced SHG response and birefringence, such as α‐BiB 3 O 6 [ 11 ] and SbB 3 O 6 . [ 12 ] However, such cations usually make the UV cutoff edge redshift, limiting their use in the short wavelength areas. In order to balance the contradiction between UV cutoff edge, birefringence and SHG response, halogen is introduced to the structural frame.…”

An Antimony(III) Fluoride Oxalate with Large Birefringence

“…Recently, in a Sn 2+ ‐containing borate, Pan's group found that the SCALP electrons of the Sn 2+ polyhedral give rise to strong optical anisotropy, which is responsible to the enhanced birefringence from Ba 2 B 5 O 9 Cl to Sn 2 B 5 O 9 Cl [8] . In addition, our group synthesized a new borate SbB 3 O 6 , which exhibits the largest birefringence among borates largely owing to the Sb 3+ with SCALP [10] . 2) Introduction of π‐conjugation groups are beneficial for large birefringence [11] .…”

Two Pyrophosphates with Large Birefringences and Second‐Harmonic Responses as Ultraviolet Nonlinear Optical Materials

“…[4] Based on mature NLO materials (b-BaB 2 O 4 ), [5] LiB 3 O 5 , [6] and KBe 2 BO 3 F 2 [7] )a nd unique birefringent crystals (a-BaB 2 O 4 ) [8] and Ca(BO 2 ) 2 [9] ), as eries of excellent UV or deep-UV NLO borates with active-NLO chromophores or halide ions have been developed. [10] Most recently,n ew [BO x F 4Àx ] (x+1)À (x = 1, 2, 3) tetrahedra with multifaceted good characteristics as building blocks were introduced, which led to as eries of high performances NLO crystals. [11] Phosphate structures are commonly rigid, which beneficial to enhance the chemical and thermally stabilities.…”