Xinxin Zhuang

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

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.

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%).