Synthesis, growth and characterization of semiorganic nonlinear optical single crystal bis(thiourea) barium nitrate (BTBN) for frequency conversion

Abstract

A novel semiorganic nonlinear optical (NLO) crystal, bis(thiourea) barium nitrate (BTBN) was synthesized and grown by slow evaporation method. Structure of the new crystalline compound was confirmed by single crystal X-ray diffraction analysis and it showed that BTBN belongs to orthorhombic crystal system. The crystalline nature of the BTBN was confirmed by powder X-ray diffraction study. Important functional groups of BTBN were identified by FT-IR spectroscopic analysis. UV-Vis-NIR spectral study showed that the grown crystal is transparent in the entire visible region with low cut off wavelength of 304 nm. BTBN exhibits a SHG efficiency which is nearly 2.38 times higher than that of KDP. The BTBN crystal has high mechanical strength and belongs to soft category, which was confirmed by micorhardness study. The thermal stability of BTBN was determined from TGA and DTA thermal study which revealed that the BTBN crystal has thermal stability up to 243.1 °C. The surface properties and presence of elements was analyzed by SEM and EDAX study, respectively.

Ag[SC(NH2)2]2F: A Laser Damage-Tolerant Infrared Nonlinear Optical Material

“…a, ,,,− In addition, compared with the reported thiourea compounds, the SHG response of Ag­[SC­(NH 2 ) 2 ] 2 F at 1064 nm is significantly increased while maintaining a wide band gap (Figure b). a, , Noteworthily, the band gap and NLO property of Ag­[SC­(NH 2 ) 2 ] 2 F are also comparable with those of other excellent UV NLO crystals such as LiHgPO 4 (4.03 eV, 11 × KDP), [ o -C 5 H 4 NHOH] 2 [I 7 O 18 (OH)]·3H 2 O (3.90 eV, 8.5 × KDP), and Pb 3 Mg 3 TeP 2 O 14 (4.5 eV, 13.5 × KDP) …”

“…One such organic ligand is SC(NH 2 ) 2 (tu). Some of its metal complexes form polar or NCS structures and showed moderate SHG responses: Te(CS(NH 2 ) 2 ) 4 (SO 4 )• 2H 2 O (2.40 × KDP, KDP = KH 2 PO 4 ), 33 Ba(CS-(NH 2 ) 2 ) 2 (NO 3 ) 2 (2.38 × KDP), 34 Sn(CS(NH 2 ) 2 ) 2 Br 3 (2.08 × KDP), 35 and Sr(CS(NH 2 ) 2 ) 2 Cl 2 (1.54 × KDP). 36 We deem that their complexes with Ag + cations can form inorganic frameworks based on AgS 4 tetrahedra as in AGS and they could display high SHG responses with enhanced birefringence to achieve phase-matching.…”

Te(CS(NH2)2)4SO4·2H2O: A Three-in-One Semiorganic Nonlinear Optical Crystal with an Unusual Quadrilateral (TeS4)6– Chromophore

“…28−44 The type of semiorganic material has usually been considered to possess the advantages of both organic and inorganic compounds. 45 Extensive investigation in this direction resulted in the discovery of a series of semiorganic NLO crystals, such as Zn(CS(NH 2 ) 2 ) 3 SO 4 , 44 MgZn(CS(NH 2 ) 2 ) 3 SO 4 , 42 Ba(CS-(NH 2 ) 2 ) 2 (NO 3 ) 2 , 39 and Cd(CS(NH 2 ) 2 ) 2 Cl 2 . 32 Whereas, we have noticed that only a few Te(II)(tu)-containing semiorganic crystals have been reported, which are mainly the complexes of thiourea and metal halides found over 30 years ago.…”

“…Notably, organic groups with similar π-conjugated configurations such as CO­(NH 2 ) 2 (carbamide), CS­(NH 2 ) 2 (thiourea = tu), [C­(NH 2 ) 3 ] + , (C 3 N 3 O 3 ) 3– , 4-hydroxypyridine, and so on are also alternative NLO-active FBUs. − For decades, the CS­(NH 2 ) 2 group with large dipole moment attracted sustained attention as an interesting FBU for linear or NLO materials . Because of its electroneutrality, this group has been widely used in the synthesis of semiorganic materials by combining them with other inorganic compounds. − The type of semiorganic material has usually been considered to possess the advantages of both organic and inorganic compounds . Extensive investigation in this direction resulted in the discovery of a series of semiorganic NLO crystals, such as Zn­(CS­(NH 2 ) 2 ) 3 SO 4 , MgZn­(CS­(NH 2 ) 2 ) 3 SO 4 , Ba­(CS­(NH 2 ) 2 ) 2 (NO 3 ) 2 , and Cd­(CS­(NH 2 ) 2 ) 2 Cl 2 .…”

“…Because of its electroneutrality, this group has been widely used in the synthesis of semiorganic materials by combining them with other inorganic compounds. − The type of semiorganic material has usually been considered to possess the advantages of both organic and inorganic compounds . Extensive investigation in this direction resulted in the discovery of a series of semiorganic NLO crystals, such as Zn­(CS­(NH 2 ) 2 ) 3 SO 4 , MgZn­(CS­(NH 2 ) 2 ) 3 SO 4 , Ba­(CS­(NH 2 ) 2 ) 2 (NO 3 ) 2 , and Cd­(CS­(NH 2 ) 2 ) 2 Cl 2 . Whereas, we have noticed that only a few Te­(II)­(tu)-containing semiorganic crystals have been reported, which are mainly the complexes of thiourea and metal halides found over 30 years ago. , Further, almost all of them crystallized into centrosymmetric space groups or P 4 3 2 1 2 space group with an effective SHG coefficient equal to zero.…”