Crystal characterization and optical spectroscopy of Eu^(3+)-doped CaGdAlO_4 single crystal fabricated by the floating zone method

A highly transparent Eu3＋-doped CaGdA104 （CGA） single crystal is grown by the floating zone method. The segregation coefficient, x ray diffraction, and x ray rocking curve are detected, and the results reveal that the single crystal is of high quality. The f-f transitions of Eu3＋ in the host lattice are discussed. The 5D0-7F2 emis- sion transition at 621 nm （red light） is dominant over the 5D0-7F1 emission transitions at 591 and 599 nm （orange light）, agreeing well with the random crystal environment of Eu3＋ ions in a CGA crystal. The decay time of Eu：5D0 is measured to be 1.02 ms. All the results show that the Eu：CGA crystal has good optical char- acterization and promises to be an excellent red- fluorescence material.

Single Crystal Growth and Physical Property Characterization of Non-centrosymmetric Superconductor PbTaSe_2

We report on the single crystal growth and superconducting properties of PbTaSe2 with the non-centrosymmetric crystal structure. By using the chemicM vapor transport technique, centimeter-size single crystals are success- fully obtained. The measurement of temperature dependence of electricaJ resistivity p（T） in both normal and superconducting states indicates a quasi-two-dimensional electronic state in contrast to that of polycrystalline samples. Specific heat C（T） measurement reveals a bulk superconductivity with Tc ≈ 3.75K and a specific heat jump ratio of 1.42. All these results are in agreement with a moderately electron-phonon coupled, type-g Bardeen-Cooper-Schrieffer superconductor.

SYNTHESIS AND CHARACTERIZATION OF A NEW THREE-ARMS-NINE-CHAINS DISCOTIC LIQUID CRYSTAL

A new three-arms-nine-chains discotic molecule has been synthesized,and the aggregation structure of the compound was measured by x-ray diffraction,infrared spectra,polarizing microscope,etc.From these evidences,the new discotic liquid crystal is found to have the discotic lammelar phase.

A DIACETYLENE CONTAINING α-NITRONYL NITROXIDE——SYNTHESIS,CRYSTAL STRUCTURE AND MAGNETIC CHARACTERIZATION

The mono-α-nitronyl nitroxide substituted diacetylene was synthesized and its structure was established by EA,FAB-MS,IR,ESR and x-ray diffraction analysis.Using the Extracting Sample Magnetometer,its magnetic properties was investigated,and the results indicate that this compound possesses antiferromagnetic properties.

SYNTHESIS,CHARACTERIZATION AND CRYSTAL STRUCTURES OF η~5-CH_3C_5H_4)M(CO)_2NO AND(η~5-CH_3C_5H_4)M(μ_3-NH)(μ_2-NO)(μ_2-CO)Fe_2(CO)_6(M=Mo or W)

Synthesis of complexes（η;-CH;C;H;）M（CO）;NO（M=Mo,I;M=W,II）and clusters（η;-CH;C;H;）M（μ;-NH）(μ;-NO) （μ;-CO）Fe;（CO）;（M=Mo,III:M=W,IV）,based on the reaction of （η;-C5;）M（CO）;Cl with Na[Fe（CO）;NO] at room tem-perature,have been demonstrated,The crystal structures of II and IV arealso presented.

SYNTHESIS AND CHARACTERIZATION OF A SERIES OF NOVEL INORGANIC MICROPOROUS CRYSTALS,BePO_4-CIn(n=4-7).

A series of novet beryllophosphate zeolites,named BePO_4-CIn(n=4-7), are synthesized hydrothermally and characterized with X-ray powder diffraction,IR spectra,SEM,thermat analysis and ion-exchange.

Solvothermal Synthesis and Characterization of [TM(1,2-dap)3]HgSb2Se5(TM = Co,Fe)with a Chain Structure

One organic-decorated quanternaery [TM（1,2-dap）3]Hg Sb2Se5（1,2-dap = 1,2-dianinopropane, TM = Co（1）, Fe（2）） compound has been solvothermally synthesized. The compounds crystallize in triclinic space group P 1, with a = 11.248（6）, b = 11.542（7）, c = 12.180（12） A, V =1268.7（16） A^3, Z = 2, F（000） = 1010 for 1 and a = 11.311（5）, b = 11.558（5）, c = 12.180（9） A, V =1276.5（12） A^3, Z = 2, F（000） = 1008 for 2. The crystal structure consists of one-dimensional anionics chains composed of Hg Se4 tetrahedra and SbSe3 trigonal pyramids sharing corners and[TM（dap）3]^2＋ cations. The [HgSb2Se＋5^2-]∞ anionic chains run along the [001] direction, and are surrounded by the [TM（dap）3]^2＋ cations. Meanwhile, 8-ring [Hg2Sb2Se4] and 6-ring [HgSb2Se2] are alternately found. The compounds were structurally characterized by elemental analysis,thermogravimetric analysis, infrared spectroscopy and UV-Vis diffuse reflectance spectroscopy.

Characterization of planar photonic crystals using surface coupling techniques at large wavelengths

We report a non-destructive characterization of planar two-dimensional （2D） photonic crystals （PhCs） made in silicon on insulator （SOI） wafers using ellipsometric or Fourier transformed infrared （FTIR） spectroscope. At large wavelengths, devices behave as homogeneous isotropic materials defined by an effective filling factor. The experimental results related to the PhC limited dimensions confirm this characterization.

Thermo-optic characterization of KDP single crystals by a modified Snarmont setup for electro-optic modulation system

For our KDP crystal orientation, various tbermo-optic （TO） and relevant temperature-dependence param- eters are defined, presented, and studied in the framework of a transverse and a longitudinal electro-optic （EO） modulation systems. This study is based on the concept of the so-called opto-electrical bias （~） ap- plied to the system. For both of the above EO-modulation systems, a set of original equations is extracted and investigated with regard to each of the more important TO or temperature coefficients. Using these equations, for these parameters the role of the transverse configuration is examined in comparison with its corresponding longitudinal configuration. A comparison is done with other orientation of the same KDP crystal.

Characterization of external refractive index sensitivity of a photonic crystal fiber long-period grating

Long-period gratings （LPGs） are fabricated in a photonic crystal fiber （PCF） using the symmetric point- by-point CO2 laser irradiation method to explore the sensitivity characterization of PCF-LPG. Numerical sim- ulation is used to guide the investigation. It is found that the refractive index （RI） sensitivity of PCF-LPG depends on the coupled cladding modes as well as the coupled resonance wavelength （RW） of the LPG. Experimental studies show that the longer the RW, the higher the RI sensitivity for the same cladding mode. At similar RWs, the lower the cladding mode, the higher the RI sensitivity of PCF-LPG.

Synthesis and characterization of molecular sieve Ni-ZSM-5 and its single crystal

Using tetrapropylammonium bromide(TPABr)as a template,molecular sieve Ni-ZSM-5 and its single crystals were synthesized in a nonalkaline system in the presence of fluoride ions.By means of XRD,IR,EPMA,MAS NMR,EPR,DTA and H_2-TPR techniques,it is proved that the hetero-atom,nickel,is really located in the zeolite framework.And finally,Ni-ZSM-5 was found to have high catalytic cracking reactivity.

Characterizing a liquid crystal spatial light modulator at oblique incidence angles using the self-interference method

The phase modulation characteristics of a reflective liquid crystal （LC） spatial light modulator （SLM） under oblique incidence are studied by using our proposed self-interference method. The experimental setup of the method is very simple and has good robustness to mechanical vibrations. By changing the gray value of the combined grayscale loaded on the LC-SLM, different sheared fringe patterns, generated by the interference between the constant phase-modulated beam and the ＋1-order diffracted beam of the blazed grating, can be obtained. The amount of phase modulation of the LC-SLM is obtained by subtracting the phase of the two side lobes in the frequency domain. By turning the turntable where the SLM is mounted, the phase modulation characteristics at different incident angles can be measured. The experimental results show that the phase modulation curves do not change significantly with the small angle. When the angle is large （i.e. larger than 10°）, the phase modulation curves become different, especially for the high gray levels. With the increase of the incident angle, the phase modulation depth is reduced. The results indicate that the incident angle plays an important role in the performance of the phase modulation of an LC-SLM.

High Temperature Stress Rupture Anisotropy of a Ni-Based Single Crystal Superalloy

High temperature stress rupture anisotropies of a second generation Ni-base single crystal（SC） superalloy specimens with [001], [011] and [111] orientations under 900 ℃/445 MPa and 1100 ℃/100 MPa have been investigated in the present study, with attentions to the evolution of γ/γ′ microstructure observed by scanning electron microscopy and the dislocation configuration characterized by transmission electron microscopy in each oriented specimen. At 1100 ℃/100 MPa as well as 900 ℃/445 MPa, the single crystal superalloy exhibits obvious stress rupture anisotropic behavior. The [001] oriented specimen has the longest rupture lifetime at 900 ℃/445 MPa, and the [111] oriented sample shows the best rupture strength at 1100 ℃/100 MPa. While the [011] oriented specimen presents the worst rupture lifetime at each testing condition, its stress rupture property at 1100 ℃/100 MPa is clearly improved, compared with900 ℃/445 MPa. The evident stress rupture anisotropy at 900 ℃/445 MPa is mainly attributed to the distinctive movement way of dislocations in each oriented sample. Whereas, at 1100 ℃/100 MPa, together with the individual dislocation configuration, the evolution of γ/γ′ microstructure in each orientation also plays a key role in the apparent stress rupture anisotropy.

Photochemical Synthesis, Properties and X-Ray Crystal Structure of Tetrabutylammonium Dodecamolybdophosphate Heteropoly Blue

The title heteropoly blue, (Bu_4N)_6H_(10)[PMo_(11)~ⅥMo~ⅤO_(40)]_4·H_2Ohas been photochemically synthesized and characterized with elemental analysis, solid diffusionreflectance electronic spectra, CV, ESR, XPS, IR spectra, conductivity measurement and X-ray singlecrystal analysis. The crystallographic data for C_(96)H_(218)Mo_(48)N_6O_(169)P_4 are as follows:M_r = 8889.76, triclinic, P_1, a = 1.4142(3) nm, b = 2.6027(5) nm, c = 2.6403(5) nm, α=113.96(3)°, β = 90.05(3)°, γ= 105.71(3)°, V = 8.481(3) nm^3, Z = 1, D_c = 1.741 g/cm^3, F(000)= 4264, μ= 1.798 mm^(-1). The X-ray crystal structure analysis reveals that there is oneindependent molecule in the unit cell of the title heteropoly blue which contains four mixed-valenceheteropoly anions, six tetrabutylammonium cations and one water molecule. Its molecular structurepossesses a centrosymmetrical arrangement in the unit cell. The phosphorus atom is in thecrystallographic inversion center of the heteropoly anion and the eight oxygen atoms surroundingcentral phosphorus atom comprise of a distorted hexahedron. Heteropoly anion has two equal sets ofPO_4 tetrahedron. The PO_4 tetrahedron and the MoO_6 octahedron in the polyanion are greatlydistorted.