http://nopr.niscair.res.in/handle/123456789/12451 Search the Channel search http://nopr.niscair.res.in/simple-search http://nopr.niscair.res.in/handle/123456789/12461 Title: Synthesis, crystal structure and characterization of Na_2.02Ag_5.98[GaSiO₄]₆(NO₂)₂and Na_3.12K_4.88[GaSiO₄]₆(NO₂)₂ sodalites <br/> <br/>Authors: Borhade, A V; Wakchaure, S G <br/> <br/>Abstract: Partially exchanged silver and potassium derivatives of Na₈[GaSiO₄]₆(NO₂)₂sodalite, Na_2.02Ag_5.98[GaSiO₄]₆(NO₂)₂and Na_3.12K_4.88[GaSiO₄]₆(NO₂)_2,have been studied. The nitrite sodalite of the composition, Na₈[GaSiO₄]₆(NO₂)₂was prepared at low temperature by hydrothermal technique and the derivatives Na_2.02Ag_5.98[GaSiO₄]₆(NO₂)₂and Na_3.12K_4.88[GaSiO₄]₆(NO₂)_2,were obtained by cation exchange method at 373 K. These products crystallize with the cubic sodalite structure in the space group P43n and profile refinement of powder X-ray data has been completed. The products obtained were studied by different investigative techniques like IR spectroscopy, X-ray powder diffraction, UV-DRS and SEM. FTIR study shows shift in absorption frequency for the exchange of silver and potassium derivatives. The unit cell parameters (<i>a</i>) are found to be 8.9328, 8.9838 and 9.0409 Å for silver, sodium and potassium sodalites, respectively, while the bond distances and bond angles are modified considerably. UV-DRS study shows shift in bands and change in band gap energy of these sodalite derivatives. SEM shows surface morphology of these sodalites. <br/> <br/>Page(s): 563-567 Fri, 29 Jul 2011 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/12460 Title: Hybrid nano-crystalline TiO₂solar cell with copper phthalocyanine as sensitizer and hole transporter <br/> <br/>Authors: Rajkumar; Sharma, G D; Roy, M S <br/> <br/>Abstract: Bulk heterojunction photovoltaic devices based on blends of copper phthalocyanines as electron donor and crystalline nc-TiO₂nanoparticles as electron acceptor have been studied. Compositions of nc TiO₂:CuPc films are cast from a common solvent mixture. In this device, CuPc has been used both as sensitizer and electron donor. The photoinduced charge transfer composite thin film structure is predicted on the basis of its optical behaviour, photo action spectra and fluorescence spectra, supported by current – voltage characteristics in dark and under illumination. The increase in photocurrent in composite is justified in terms of the formation of bulk heterojunction between CuPc and TiO₂ nanoparticles. The photovoltaic effect in the device made by sandwiching the active nc-TiO₂:CuPc layer between Al and ITO electrodes, has been studied as a function of the TiO₂ concentration. The experimental results support that the photoinduced photogeneration of charge carriers is induced by the production of excitons and their subsequent efficient dissociation into free carriers at increased TiO₂:CuPc (D-A) interface, which is spread over the whole bulk region sandwiched between Al and ITO. The capacitance-voltage characteristics of the device also support the formation of bulk heterojunction between CuPc and TiO₂. <br/> <br/>Page(s): 557-562 Fri, 29 Jul 2011 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/12459 Title: Thermodynamic behaviour of methylmethacrylate in methanol, <i style="">p</i>-dioxane and cyclohexane <br/> <br/>Authors: Bhandakkar, V D; Chimankar, O P; Pawar, N R <br/> <br/>Abstract: Khasare’s equation of state has been applied to the binary liquid mixture of methylmethacrylate in methanol, cyclohexane and <i style="">p</i>-dioxane. It is observed that there is close agreement with experimental one. The thermodynamics picture built up in this formulation could be considered as a good representation of molecular cluster in liquid state. <br/> <br/>Page(s): 550-556 Fri, 29 Jul 2011 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/12458 Title: Effect of Sb incorporation on the density of defect states in a-Se90In10 glassy alloy <br/> <br/>Authors: Shukla, S; Singh, S P; Kumar, S <br/> <br/>Abstract: The <i>dc</i> conductivity of thin films of Se₉₀In₁₀_-xSb_x(where <i>x</i> =0, 2, 4 and 6) glassy alloys prepared by conventional rapid melt-quenching technique at high electric fields, has been measured. Thin films of amorphous binary and ternary chalcogenide glassy alloys of Se₉₀In₁₀_-xSb_x systemare obtained by the thermal evaporation technique of bulk material on to well cleaned glass substrates. Current-voltage (<i>I</i>-<i>V</i>) characteristics have been measured at various fixed temperatures. In these samples, ohmic behaviour is observed at low electric fields. However, at high electric fields (<i>E</i>~10⁴V/cm), non-ohmic behaviour is observed. An analysis of the experimental data confirms the presence of space charge limited conduction (SCLC) in the glassy materials studied in the present case. From the fitting of the data to the theory of SCLC, the density of defect states (DOS) near Fermi level has been calculated. It is found that the DOS is increasing with increase in concentration of Sb in pure binary Se₉₀In₁₀ glassy system. These results have been explained on the basis of some structural changes with third element Sb as an impurity in the pure binary Se₉₀In₁₀ glassy alloy<b style="">*</b>. <br/> <br/>Page(s): 545-549 Fri, 29 Jul 2011 22:58:59 GMT