Genbo Su

Growth of potassium nickel sulfate hexahydrate (KNSH) crystal and its characterization

A large clear crystal of potassium nickel sulfate hexahydrate (KNSH) with a dimension of 60 x 35 x 30 mm(3) has been grown by a long stick-shaped seed of 60 x 2 x 2 mm3, in a cooling water solution. The habit and condition of growth were observed. The parameters of crystal structure, transmission spectrometry, and thermal properties are reported

A new pyroelectric crystal L-lysine-doped TGS (LLTGS)

Abstract Large clear crystal of LLTGS (TGS doped with l -lysine) with 60×27×14 (mm) has been grown by cooling an aqueous solution. The concentration of l -lysine was determined by liquid chromatography. The X-ray diffraction shows that the lattice parameters ( a , b and c ) are larger than those of pure TGS. LLTGS crystal has excellent pyroelectric properties and higher internal bias field than that of LATGS (TGS doped with l -alanine) crystal, and so it is a promising pyroelectric material for infrared detector.

Ammonium nickel sulfate hexahydrate crystal: a new ultraviolet light filter

We propounded and grew a new crystal material of ammonium nickel sulfate hexahydrate (ANSH) for an ultraviolet light filter. The crystal structure of ANSH was solved by x-ray diffraction method and the empirical formula of the title compound is (NH4)2Ni(SO4)2⋅6H2O. The ANSH crystal belongs to the monoclinic space group P21/C, a = 6.2351 A, b = 12.451(3) A, c = 9.1798(18) A, β = 106.88(3)°, v = 681.9(2) A3, z = 2 and Dc = 1.924 g cm−3. The deep-green ANSH single crystal with a dimension of 20.5×28×15 mm3 has been grown by the cooling solution method. Thermo-gravimetry analysis showed that the dehydration temperature of the ANSH crystal is above 96.06°C, which is much higher than that of commercially available nickel sulfate hexahydrate (NSH) crystals. The optical transmission character of the ANSH crystal is discontinuous in the range from ultraviolet (UV) to near IR wavelengths, and has several transmission peaks at 250 nm, 500 nm, 875 nm and 1425 nm, respectively. The UV transmission peak (250 nm) especially has high transmission efficiency and a narrow spectrum band-width. The relationship between the structure and the optical transmission property is further discussed.

Nonlinear optical properties of some derivatives of stilbene and vinyl cyanide

Three derivatives of stilbene: 3-hydroxy-4-methoxy-4′-nitrostilbene (HMONS), 3-methoxy-4-hydroxy-4′-nitro-stilbene (MOHNS), 2-cyano-3-indole-propenoic acid ethyl ester (CIP-ethyl), and one derivative of vinyl cyanide: p-1,1-dicyano-vinyl-dimethylaminoaniline (DVDA) were designed and synthesized. The powder second-harmonic generation and absorption spectra of these four compounds were measured. First principle calculation of the molecular first hyperpolarizabilities of HMONS were calculated and compared with those of 3-methyl-4-methoxy-4′-nitrostilbene (MMONS, Appl. Phys. Lett. 56 (1990) 423) in order to elucidate their structural origin of the optical nonlinearity.

Growth of α-nickel sulphate hexahydrate for ultraviolet filters

Abstract Large clear crystals of α-nickel sulphate hexahydrate with dimensions of 65 × 85 × 75 (mm 3 ) have been grown by cooling an aqueous solution. The habit and condition of growth were observed. The grown crystals were optically characterized.

New technology of KDP crystal growth

A new technology of KDP crystal growth is proposed for crystals grown at {101} or {011} pyramidal face seed. By the Holden method using temperature reduction, large single crystals were obtained. The grown crystals were optically characterized.

Large γ-CuI semiconductor single crystal growth by a temperature reduction method from an NH4I aqueous solution

NH4I has been proven to be a promising cosolvent for cuprous iodide (CuI) single crystal growth from aqueous solutions by the temperature reduction method. In our work, as compared with NH4Cl and NH4Br, NH4I offers more advantages for single crystal growth, such as by remarkably increasing the solubility and growth rate of CuI crystals, effectively reducing the impurity concentration, and enhancing the crystal quality and crystallinity. A regular, centimeter-sized, high optical quality single crystal was successfully obtained using NH4I as a cosolvent. The electronic and optical properties of the as-grown crystal were characterized by Hall-effect measurements and optical transmission and photoluminescence spectra, respectively. The results demonstrated that the CuI crystal is conductive (high p-type mobility of 12.81 cm2 V−1 s−1) and transparent (great transmittance over 80%).

The study of ANSH crystallization from solution with concentration measurement by magnetic weigh method

Abstract A new design on solution density measurement described as the magnetic weigh method (MWM) is introduced. Inline solute concentration can be determined based on the definite relationship to the density of the solution. Several seed crystals have been used for crystallization in the study. The variances of excess saturation ratio S recorded by MWM show that seed crystals start to grow remarkably at S=0.13 and the crystallization rate is in proportion to S in spite of the crystal surfaces enlarged simultaneously. The ratio of linear and parabolic growth rates initially is analyzed to be approximately 3:2 and at low supersaturated concentration, the mechanism of the growth of crystal is deduced as diffusion and transport adsorption at the growing surface.

New organic nonlinear optical crystals of 1-(3-thienyl)-3-(4-bromophenyl)-propene-1-one

Abstract A new organic nonlinear optical crystal 1-(3-thienyl)-3-(4-bromophenyl)-propene-1-one (BTC) with a powder second harmonic generation (SHG) efficiency 100 times larger than that of potassium dihydrogen phosphate (KDP) and with a cutoff wavelength of 410 nm is reported. Large single crystals (30 × 7 × 1mm 3 ) were grown by the evaporation method in acetone. The crystal structure of BTC is determined.