M. Esthaku Peter; P. Ramasamy
Abstract
Single crystals of triglycinium calcium nitrate, a semiorganic nonlinear optical (NLO) material, have been grown by slow solvent evaporation technique at room temperature. The size of the grown crystal is up to the dimension of 29×19×5 mm 3 . The structure of the crystal was analyzed by single ...
Read More
Single crystals of triglycinium calcium nitrate, a semiorganic nonlinear optical (NLO) material, have been grown by slow solvent evaporation technique at room temperature. The size of the grown crystal is up to the dimension of 29×19×5 mm 3 . The structure of the crystal was analyzed by single crystal X-ray diffraction and the functional groups present in the sample were identified by FTIR spectral analysis in the range 4000-450 cm -1 . The UV-vis-NIR studies was undertaken to find the transmittance in the ultraviolet and visible region. The efficiency of second harmonic generation was analyzed by Kurtz-Perry powder technique and compared with standard KDP crystal. Thermogravimetric and differential thermal analysis have been performed to determine the thermal stability of the crystal. Dielectric properties such as dielectric constant and dielectric loss were studied at various temperatures and frequencies. Vickers microhardness testing was carried out on the as-grown crystal surface to reveal the mechanical properties of the crystal. Etching studies were made on the as grown crystal to analyze the structural imperfection of the crystal.
Anand Kumar Tripathi; Mohan Chandra Mathpal; Promod Kumar; Vivek Agrahari; Manish Kumar Singh; Sheo Kumar Mishra; M. M. Ahmad; Arvind Agarwal
Abstract
The Ni doped titania nanostructures were synthesized by sol-gel method followed by calcination at 400°C for one hour. The optical band gap for these nanostructures indicates the red shift. The doped TiO2 nanostructures are spherical in shape. The pure TiO2 exhibits all the possible emission bands ...
Read More
The Ni doped titania nanostructures were synthesized by sol-gel method followed by calcination at 400°C for one hour. The optical band gap for these nanostructures indicates the red shift. The doped TiO2 nanostructures are spherical in shape. The pure TiO2 exhibits all the possible emission bands while Ni-doped TiO2 nanoparticles show blue-green emission bands. The results suggest that Ni2+ replace some Ti 4+ in TiO2 lattice with tensile strain while TiO2 remained in the form of anatase phase, reduces its band gap energy. The synthesized TiO2 exhibits enhanced photoconducting properties. The work suggest that the titania based materials can have potential applications in photovoltaics, optoelectronic devices and photoconductors in replacement of expansive materials by controlling the compositions and morphology of the nanostructures.
