Growth,Structural,Optical and Hardness Studies of Lithium Potassium Sulphate Single Crystals--An Inorganic NLO Material

Single crystal of lithium potassium sulphate, a nonlinear optical material, was grown from aqua solution by slow evapo- ration method at room temperature. The cell parameters were estimated by single crystal X-ray diffraction analysis. The optical transmittance of the crystal was recorded using the UV-Vis-NIR spectrophotometer and the optical band gap was calculated using this method. The second harmonic generation efficiency was measured by Kurtz and Perry powder technique and the phase-matching property was confirmed. The hardness of the material was measured by Vicker’s hardness test.

Synthesis and Characterizations of Rare Earth Compounds RE(HCO_2)_3(HNO_2)(H_2CO_2)(RE=Y,Tb,Dy,Ho,Er,Yb,Tm)

A series of novel inclusion compounds with compositions of RE(HCO 2) 3(HNO 2)(H 2CO 2) (RE=Y, Tb, Dy, Ho, Er, Yb, Tm) were synthesized and structures were characterized by X ray methods. The orthorhombic structure was shown to be a new type with a non centrosymmetric space group (20) C 222 1 by single crystal structure determinations. It is characterized by networks of rare earth centered square anti prisms formed by eight oxygen atoms through bridging carbon and nitrogen atoms. The guest formic acid molecules H 2CO 2 are distributed inside the open tunnels along the crystallographic a axis. The magnetic susceptibility measurements show the heavy rare earth compounds follow the Curie Weiss law and the calculated numbers of Bohr magnetons are consistent with the RE 3+ ions. The yttrium compound shows very weak temperature independent paramagnetism.

Synthesis of 3-Biaryl-1-ferrocenyl-2-propene-1-ones

The novel structures of organometallic compounds 3-biaryl-1-ferrocenyl-2-propene- 1-ones 5 were synthesized for nonlinear optical chromophores by Suzuki cross-coupling reaction. Their structures were determined with elemental analyses, 1H NMR spectra and 13C NMR spectra.

Palladium Catalyzed Synthesis of Fluorine-containing 3-Biaryl-1-ferrocenyl-2-propene-1-one

The novel organometallic compounds, 3-[4'(or 2')-(4''-fluorophenyl)] phenyl-1-ferroc- enyl-2-propen-1-ones 5 were synthesized for nonlinear optical chromophores by Pd (0) catalyzed Suzuki cross-coupling reaction. Their structures were established with elemental analysis, MS, IR and H NMR spectroscopies. 1

Growth and Solvent Effects of a Promising Nonlinear Optical Sodium Paranitrophenolate Dihydrate (NO_2-C_H_4-ONa·2H_2O) Single Crystal

Sodium paranitrophenolate dihydrate (NPNa·2H2O) is an excellent semiorganic nonlinear optical (NLO) material, crystallizes both in water and methanol with high degree of transparency. Good optical quality single crystals of dimension upto 18 mm×6 mm×3 mm are obtained by isothermal solvent evaporation technique. The solubility of the crystal in different solvents was measured gravimetrically. The single crystals of NPNa·2H2O show variation in physical properties and growth rate in different solvents. Methanol or ethanol solution yields crystals of bipyramidal shape with clear morphology. However, methanol grown crystal is exhibiting improved hardness parameters and possesses excellent thermal stability as compared to water grown crystals. The effects of solvent on hardness parameter along with thermal and optical properties of NPNa·2H2O was revealed in this paper.

Recent progress on sulfide infrared nonlinear optical materials with large SHG response and wide band gap

As the core device of all-solid-state laser,infrared(IR)nonlinear optical(NLO)material plays a critical role in exploring new coherent lights by frequency conversion technologies,which are widely used in noninvasive medical diagnostics,spectroscopy,environmental monitoring and long-distance laser communication.To satisfy the growing demand of current laser technology in IR regions,high performance NLO materials with large second-harmonic generation(SHG)response,high laser-induced damage threshold(LIDT)and wide transparency range are highly expected.Recently,numerous efforts and advances have been achieved in sulfide system.This review highlights the progress of high-performance sulfide IR NLO materials with a good balance between strong SHG response(≥1.0×AgGaS_(2))and wide band gap(≥3.0 eV)since 2018.The chemical synthesis,crystal structure,optical properties and structure-property relationship of 13 high performance metal sulfide IR NLO materials are summarized and reviewed in detail.Finally,the potential opportunities and challenges in IR NLO materials are discussed.

非线性光学数据库:理论预测助力材料的快速发现

现代激光技术迫切需要能够通过二次谐波产生相干光的非线性光学材料.然而,只有很少一部分非中心对称晶体材料的非线性光学性质被实验或者理论研究,针对高性能非线性光学晶体材料的探索仍非常有限.本工作建立了迄今为止最大的计算非线性光学晶体材料数据库,其中包含2354个非中心对称晶体结构,以及它们的倍频系数和带隙.本文提供了理论数据的计算细节和其与实验数据的对比验证,以及数据库的详细描述.该数据库的重要特点之一是它包含大量通过进化算法搜索发现的新的热力学稳定和亚稳定结构,这为寻找具有更好性能的新型非线性光学材料提供了可能性.

Synthesis and nonlinear optical properties of copolymers of fluoro-containing bisphenol A and chromophores

A series of new fluoro-containing copolymers have been synthesized by a Mitsunobu reaction with 4,4＇-（hexafluoroisopropylidene） bisphenol A（6FBPA） and the corresponding N,N-dihydroxyethylaminoaryl azo or ring-locked triene compounds, which have high thermal stability and good solubility in organic solvents.The nonlinear optical（NLO） measurements made by Marker fringe method at 1064 nm indicate that the copolymers embedded with the ring-locked triene and azo chromophores exhibit higher macroscopic nonlinear optical coefficient（70.2 pm/V and 26.5-34.6 pm/V,respectively）.Thermal analysis and UV-visible absorption spectra show that the copolymers have good thermal stability（T_d= 264-319℃） and optical transparency （λ_（max）500 nm）.

Syntheses,characterization and calculations of LimAnM6O15(A=Rb,Cs;M=Si,Ge;m+n=6)

Alike phosphates,silicates and germanates exclusively containing tetrahedral basic building units(BBUs)can also exhibit ultraviolet(UV)even deep-UV transitions.They are important for the design of new UV or deep-UV nonlinear optical(NLO)materials.In this paper,four new alkali metal silicates and germanates,Li2Rb4Si6O15,Li2Cs4Si6O15,Li3Rb3Ge6O15 and Li3Cs3Ge6O15 were successfully synthesized by a high temperature solid state reaction.They obey the general formula of LimAnM6O15(A=Rb,Cs;M=Si,Ge;m+n=6)and all exhibit the Sr2Be2B2O7(SBBO)-like structures.More importantly,Li3Rb3Ge6O15 and Li3Cs3Ge6O15 crystallize in the noncentrosymmetric(NCS)structures and exhibit remarkable phase-matched second harmonic generation(SHG)effect,0.8×KH2PO4(KDP)and 1×KDP,respectively.These indicate that they are potential as UV or deep-UV NLO materials.Furthermore,their optical and NLO properties as well as thermal properties were measured.The structure-property relationships were studied by the dipole moment calculations and the first-principles calculations.