Nonlinear optical properties of [（CH3）4N]Au（dmit）2 using Z-scan technique

The third-order optical nonlinearities of [（CH3）4N]Au（dmit）2 （dmit = 4,5-dithiolate-1,3-dithiole-2-thione） at 532 nm and 1064 nm are investigated using the Z-scan technique with pulses of picoseconds duration. The Z-scan spectra reveal a strong nonlinear absorption （reverse saturable absorption） and a negative nonlinear refraction at 532 nm. No nonlinear absorption is observed at 1064 nm. The molecular second-order hyperpolarizability γ for the [（CH3）4N]Au（dmit）2 molecule at 532nm is estimated to be as high as （2.1 ±0.1） × 10^-31 esu, which is nearly three times larger than that at 1064 nm. The mechanism responsible for the difference between the results is analysed. Nonlinear transmission measurements suggest that this material has potential applications in optical limiting.     

Measurement of thermophysical properties of YBa2Cu3O7−x thin film using picosecond thermoreflectance technique

Simultaneous determination of thermophysical properties of YBa₂Cu₃O_7?x thin film has been carried out using the optical pump–probe method. The thermal diffusivity and thermal effusivity were analyzed from the same picosecond thermoreflectance data. The thermal conductivity and specific heat were then derived from the measured values of the thermal diffusivity and effusivity. The thermal diffusivity, thermal effusivity and thermal conductivity obtained compared favorably with those reported in the literature.     

Nonlinear optical absorption in Bi3TiNbO9 thin films using Z-scan?technique

Bi₃TiNbO₉ (BTN) thin films with layered perovskite structure were fabricated on fused silica by pulsed laser deposition. The XRD pattern revealed that the films are single-phase perovskite and highly (00l) textured. Their fundamental optical constants, such as band gap, linear refractive index, and linear absorption coefficient, were obtained by optical transmittance measurements. The dispersion relation of the refractive index vs. wavelength follows the single electronic oscillator model. The nonlinear optical absorption of the films was investigated by single beam Z-scan method at a wavelength of 800 nm with laser duration of 80 fs. We obtained the nonlinear absorption coefficient β=1.44×10⁻⁷ m/W. The results show that the BTN thin films are promising for applications in absorbing-type optical devices.     

Structural and optical properties of CuSe2 nanocrystals formed in thin solid Cu–Se film

This paper describes the structural and optical properties of Cu–Se thin films. The surface morphology of thin films was investigated by atomic force microscopy (AFM) and scanning electron microscopy (SEM). Formation of Cu–Se thin films is concluded to proceed unevenly, in the form of islands which later grew into agglomerates. The structural characterization of Cu–Se thin film was investigated using X-ray diffraction pattern (XRD). The presence of two-phase system is observed. One is the solid solution of Cu in Se and the other is low-pressure modification of CuSe₂. The Raman spectroscopy was used to identify and quantify the individual phases present in the Cu–Se films. Red shift and asymmetry of Raman mode characteristic for CuSe₂ enable us to estimate nanocrystal dimension. In the analysis of the far-infrared reflection spectra, numerical model for calculating the reflectivity coefficient of layered system, which includes film with nanocrystalite inclusions (modeled by Maxwell-Garnett approximation) and substrate, has been applied.     

{Cu2[C12H18N2O7S]2[C10H8N2]}n聚合物的合成及晶体结构

采用铜(Ⅰ)盐和邻香草醛缩氨基甲磺酸席夫碱以及4,4'-联吡啶在乙醇溶液中合成了具有三维网状的配位聚合物,通过元素分析、红外光谱对配位聚合物进行了表征,并利用X射线单晶衍射仪对其结构进行了鉴定.晶体结构分析表明,该标题配合物属单斜晶系,空间群P2(1)/c,晶胞参数为a=1.1956nm,6=0.8464nm,c=2....     

Comparable structural and optical properties of 4H-pyrano [3, 2-c] quinoline derivatives thin films

The structural and optical properties of 2-Amino-6-ethyl-5-oxo-4-(3-phenoxyphenyl) - 5, 6- dihydro - 4H-pyrano [3,2-c] quinoline-3- carbonitrile (Ph-HPQ) and 2-Amino-4-(2-chlorophenyl)-6-ethyl-5-oxo-5,6-dihydro-4H-pyrano [3,2-c] quinoline-3-carbonitrile (Ch-HPQ) thin films are studied. The compounds are polycrystalline in as- synthesised powder form; they became nanocrystallites dispersed in amorphous matrix upon thermal deposition to form thin films. FTIR spectral measurements showed no change in chemical bonds of the compounds after being deposited to form thin films. The optical properties have been determined based on spectrophotometer measurements of transmittance and reflectance at nearly normal incidence of light in the spectral range of 200–2500 nm. The absorption parameters, molar extinction coefficient, oscillator strength and electric dipole strength, are reported. The type of electron transition is determined from analysis of absorption coefficient spectra near the onset and optical absorption edges. The onset and optical energy gaps for Ph-HPQ and Ch-HPQ thin films are determined. The single oscillator model is applied to calculate the dispersion parameters of the investigated thin films. In addition, oscillator and dispersion energies, the high-frequency dielectric constant, lattice dielectric constant and ratio of free charge carriers concentrations to their effective masses are evaluated for the compounds under investigation.     

[MnHg(SCN)4(H2O)2]·2C4H9NO(MMTWD)晶体的光谱分析

根据商群对称性分析法对MMTWD晶体的振动模作了理论计算.计算结果显示,通过实验可观察到的拉曼散射峰和红外反射带应分别不超过297和148个.运用实验的手段,分别测定晶体的拉曼光谱和红外光谱,给出了MMTWD晶体在50～3 000 cm-1范围内的拉曼光谱图和400～4 000 cm-1范围里的红外光谱图,并对光谱中的谱线作了指认.给出了MMTWD晶体的分子结构示意图,最终确定MMTWD晶体结构为三维网状结构,说明在众多新型光功能材料当中MMTWD晶体是一种更适合生长成较大尺寸且稳定性较好的非线性光学晶体,在光电子领域中具有良好的应用前景.     

糖精钴水合物[Co(C7H4NO3S)2(H2O)4]·2H2O的合成及晶体结构

以糖精钠(sac-Na)、丙氨酸和硝酸钴为原料合成得到糖精钴琥珀色块状晶体,采用红外、X射线单晶衍射对配合物进行了表征,该晶体属单斜晶系,空间群为P21/c,晶胞参数为:a=0.79269(5)nm,b=1.61407(10)nm,c=0.77026 (5) nm,α=90°,β=99.695(7)°,Ⅴ=0.97145 (11) nm3,Z=2,Dc=1.817g/cm3,F(000)=546,R=0.0278.结构分析表明,中心Co离子与4个O原子和两个N原子配位,处于四角双锥八面体配位环境中,4个水分子在赤道平面上与Co离子配位,晶胞中还包含有2个游离的结晶水,形成了含6个水分子的结晶物.     

Thermal annealing effect on structural and optical properties of 2,9-Bis [2-(4-chlorophenyl)ethyl] anthrax [2,1,9-def:6,5,10-d′e′f′] diisoquinoline-1,3,8,10 (2H,9H) tetrone (Ch-diisoQ) thin films

Thin films of 2,9-Bis [2-(4-chlorophenyl)ethyl] anthrax [2,1,9-def:6,5,10-d′e′f′] diisoquinoline-1,3,8,10 (2H,9H) tetrone (Ch-diisoQ) were prepared by thermal evaporation technique. Structural properties of these (as-prepared and annealed at 373, 423, 473 and 523 K) films were determined by X-ray diffraction and scanning electron microscopy, which showed that the grain sizes increasing by the annealing effect. The transmittance and reflectance of all Ch-diisoQ thin films were measured in the range 200–2500 nm. Some optical constants such as optical band gap (E _g ), dispersion energy (E _d ), single oscillator energy (E _o ) and optical dielectric constant at a higher frequency (ε _∞ ) were calculated at different annealing temperatures. The optical band gap of the samples is decreased with the increase of annealing temperatures due to the increasing of the π-dislocation. Finally, the values of the optical susceptibility, χ⁽³⁾, were found to be annealing dependence.     

混配配合物[Co(cpida)(C7H5N2)2]·C7H5N2·5H2O

在溶液中用N-(邻苯甲酸基)-亚氨基二乙酸、苯并咪唑和Co(Ac)2·4H2O进行自组装合成了标题三元金属混配配合物.用元素分析、红外光谱、单晶衍射对配合物的组成和结构进行了表征,确定配体N-(邻苯甲酸基)-亚氨基二乙酸中的3个羧基为单齿形式与中心金属钴离子配位.     

The structural transformation of monoclinic [(R)-C5H14N2][Cu(SO4)2(H2O)4]·2H2O into orthorhombic [(R)-C5H14N2]2[Cu(H2O)6](SO4)3: crystal structures and thermal behavior

Single crystals of [(R)-C₅H₁₄N₂][Cu(SO₄)₂(H₂O)₄]·2H₂O (1) were grown through the slow evaporation of a solution containing H₂SO₄, (R)-C₅H₁₂N₂ and CuSO₄·5H₂O. These crystals spontaneously transform to [(R)-C₅H₁₄N₂]₂[Cu(H₂O)₆](SO₄)₃ (2) over the course of four days at room temperature. The same single crystal on the same mounting was used for the determination of the structure of (1) and the unit cell determination of (2). A second single crystal of the transformed batch has served for the structural determination of (2). Compound 1 crystallizes in the noncentrosymmetric space group P2₁ (No. 4) and consists of trimeric [Cu(SO₄)₂(H₂O)₄]^2? anions, [(R)-C₅H₁₄N₂]²⁺ cations and occluded water molecules. Compound 2 crystallizes in P2₁2₁2 (No. 18) and contains [Cu(H₂O)₆]²⁺ cations, [SO₄]^2? anions and occluded water molecules. The thermal decompositions of compounds 1 and 2 were studied by thermogravimetric analyses and temperature-dependent X-ray diffraction.     

A new acentric borate of K2Ba[B4O5(OH)4]2·10H2O: synthesis,structure and nonlinear optical property

A new acentric mixed metal borate of composition K₂Ba[B₄O₅(OH)₄]₂·10H₂O, has been successfully obtained by slow evaporation solution method. The compound crystallizes in the Orthorhombic space group Pna21 (No.33) with a = 16.8668(7) Å, b = 13.0903(5) Å, c = 11.5529(5) Å and Z = 4. [B₄O₅(OH)₄]^2? clusters serve as fundamental building unit linking with BaO₈, K1O₆, K2O₇ by common O atoms to form three-dimensional layer structure. The second harmonic generation measurements in the powder samples reveal that the compound exhibits approximately 0.5 times that of KH₂PO₄ (KDP) and phase matching.     

Structure and magnetotransport properties of the new quasi-two-dimensional molecular metal β″-(BEDT-TTF)4H3O[Fe(C2O4)3] · C6H4Cl2

The β″-(BEDT-TTF)₄A^I[M^III(C₂O₄)₃] · G(A^I=NH ₄ ⁺ , H₃O⁺, K⁺, Rb⁺; M^III=Fe, Cr; G = “guest” solvent molecule) family of layered molecular conductors with magnetic metal oxalate anions exhibits a pronounced dependence of the conducting properties on the type of neutral solvent molecules introduced into the complex anion layer. A new organic dichlorobenzene (C₆H₄Cl₂)-containing conductor of this family, namely, β″-(BEDT-TTF)₄H₃O[Fe(C₂O₄)₃] · C₆H₄Cl₂, is synthesized. The structure of the synthesized single crystals studied by X-ray diffraction is characterized by the following parameters: a = 10.421(1) Å, b= 19.991(2) Å, c= 35.441(3) Å, β = 92.87(1)°, V= 7374(1) ų, space groupC2/c, and Z = 4. In the temperature range 0.5&;2-300 K, the conductivity of the crystals is metallic without changing into a superconducting state. The magnetotransport properties of the crystals are examined in magnetic fields up to 17 T at T = 0.5 K. In fields higher than 10 T, Shubnikov-de Haas oscillations are detected, and the Fourier spectrum of these oscillations contains two frequencies with maximum amplitudes of about 80 and 375 T. The experimental results are compared with the related data obtained for other phases of this family. The possible structural mechanisms of the effect of a guest solvent molecule on the transport properties of the β″-(BEDT-TTF)₄A^I[M^III(C₂O₄)₃] · G crystals are analyzed.     

Structural characterization,thermal, ac conductivity and dielectric properties of (C7H12N2)2[SnCl6]Cl2·1.5H2O

(C₇H₁₂N₂)₂[SnCl₆]Cl₂·1.5H₂O is crystallized at room temperature in the monoclinic system (space group P2₁/n). The isolated molecules form organic and inorganic layers parallel to the (a, b) plane and alternate along the c-axis. The inorganic layer is built up by isolated SnCl₆ octahedrons. Besides, the organic layer is formed by 2,4-diammonium toluene cations, between which the spaces are filled with free Cl^? ions and water molecules. The crystal packing is governed by means of the ionic N—H···Cl and Ow—H···Cl hydrogen bonds, forming a three-dimensional network. The thermal study of this compound is reported, revealing two phase transitions around 360(±3) and 412(±3) K. The electrical and dielectric measurements were reported, confirming the transition temperatures detected in the differential scanning calorimetry (DSC). The frequency dependence of ac conductivity at different temperatures indicates that the correlated barrier hopping (CBH) model is the probable mechanism for the ac conduction behavior.     

Z状顺磁性化合物[{Cu(bipy)[C6H4(COO)2]}2·H2O]n和[Cu(phen)[C6H4(COO)2]]n的分子振动光谱研究

用分子振动光谱对已合成的具有顺磁性的化合物 [{Cu(bipy) [C6H4(COO) 2 ]} 2 ·H2 O]n(Ⅰ )和 [Cu( phen) [C6H4(COO) 2 ]]n(Ⅱ )进行深入研究 ,推测它们的结构 ,并将得到的结果与X射线晶体衍射测定的结构进行比较。文章对化合物的红外、拉曼光谱进行归属 ,还讨论了分子振动光谱与结构的关系     

适用于全光开关的[(C3H7)4N][Au(C3S5)2]三阶非线性光学性质研究

合成了一种金属有机配合物[(C3H7)4N][Au(C3S5)2].配制了浓度为1×10-3 mol/L的[(C3H7)4N][Au(C3S5)2]/乙腈溶液,并用旋涂法制备了掺杂浓度质量比为1%的[(C3H7)4N][Au(C3S5)2]/PMMA复合薄膜.运用Z扫描方法,分别研究了样品溶液和薄膜在波长为1064nm...     

适用于全光开关的[(C3H7)4N][Au(C3S5)2]三阶非线性光学性质研究

合成了一种金属有机配合物[(C3H7)4N][Au(C3S5)2].配制了浓度为1×10－3 mol/L的[(C3H7)4N][Au(C3S5)2]/乙腈溶液,并用旋涂法制备了掺杂浓度质量比为1%的[(C3H7)4N][Au(C3S5)2]/PMMA复合薄膜.运用Z扫描方法,分别研究了样品溶液和薄膜在波长为1 064 nm,脉宽为20 ps条件下的三阶非线性光学性质.研究发现薄膜的三阶非线性极化率χ(3)比溶液高出三个数量级.其中,薄膜的非线性折射率n2为－1.76×10－15 m2/W、三阶非线性极化率χ(3)为9.37×10－10 esu.结果表明,该材料在全光开关方面具有潜在的应用价值.     

First-principles Study on the Magnetic,Half-metal and Thermoelectric Transport Properties of Inorganic-Organic Hybrid Compounds [C4N2H12][Fe4Ⅲ(HPO3)2(C2O4)3]

The electronic structure, magnetic and half-metal properties of inorganic-organic hybrid compound [C₄N₂H₁₂][Fe₄^Ⅲ(HPO₃)₂(C₂O₄)₃] are investigated by using the full-potential linearized augmented plane wave (FPLAPW) method within density-functional theory (DFT) calculations. The density of states (DOS), the total energy of the cell and the spontaneous magnetic moment of [C₄N₂H₁₂][Fe₄^Ⅱ(HPO₃)₂(C₂O₄)₃] are calculated. The calculation results reveal that the low-temperature phase of [C₄N₂H₁₂][Fe₄^Ⅲ(HPO₃)₂(C₂O₄)₃] exhibits a stable ferromagnetic (FM) ground state, and we find that this organic compound is a half-metal in FM state. In addition, we have calculated antiferromagnetically coupled interactions, revealing the existence of antiferromagnetic (AFM), which is in agreement with the experiment. We have also found that [C₄N₂H₁₂][Fe₄^Ⅲ(HPO₃)₂(C₂O₄)₃] is a semiconductor in the AFM state with a band gap of about 0.40 eV. Subsequently, the transport properties for potential thermoelectric applications have been studied in detail based on the Boltzmann transport theory.     

光谱法研究Ni[(C4H9O)2PS2]2与氮碱的加合反应

用光谱法研究了Ni[(C4H9O)2PS2]2(NiL2)与吡啶、4-甲基吡啶、3,5-二甲基吡啶、2,4-二甲基吡啶和2,4,6-三甲基吡啶,温度为32℃时在乙醇溶剂中的加合反应.B(2,4-二甲基吡啶和2,4,6-三甲基吡啶)只能与NiL2生成一种1∶2的六配位加合物NiL2·B2,其他氮碱与NiL2生成1∶1的五配位NiL2·B和1∶2的六配位NiL2·B2两种加合物.所有五配位NiL2·B和六配位NiL2·B2加合物的吸收光谱分别由NiNS4和NiN2S4发色基团所产生.实验测定了加合反应的平衡常数lgβn和加合反应分子数n,lgβn随氮碱分子碱度pka增加而增大,且可以用经验公式来描述     

配合物[Zn(DMF)2(H2O)4]·C8Cl4O4的合成及其结构的研究

采用溶剂挥发扩散法合成了配合物单晶[Zn(DMF)2(H2O)4]·C8Cl4O4,其中DMF为N,N'-二甲基甲酰胺.配合物为三斜晶系,P-1空间群,其晶胞参数为a=0.57680(10)nm,b=0.85991(14)nm,c=1.2030(2)nm,α=95.781(3)°,β=102.074(3)°,γ=98.594(2)°,V=0.57154nm3,Z=1.Mr=585.51,Dc=1.701g/cm3,F(000)=298,μ=1.594mm-1,最终偏差因子R1=0.0315,wR2=0.0914,和R1=0.0345,wR2=0.0946,同时采用红外光谱分析、元素分析对其进行表征.