• فهرس المقالات Dielectric anisotropy

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        1 - Effect of ion trapping behavior of TiO2 nanoparticles on different parameters of weakly polar nematic liquid crystal
        Geeta Yadav Rohit Katiyar Govind Pathak Rajiv Manohar
        AbstractIn the present investigation, TiO2-doped weakly polar nematic liquid crystal (NLC) has been studied. This study mainly focuses on dielectric, electro-optical and optical properties of pure NLC and doped systems. Variation in different parameters like dielectric أکثر
        AbstractIn the present investigation, TiO2-doped weakly polar nematic liquid crystal (NLC) has been studied. This study mainly focuses on dielectric, electro-optical and optical properties of pure NLC and doped systems. Variation in different parameters like dielectric permittivity, dielectric loss, dielectric anisotropy and conductivity has been noticed. Permittivity of the doped system is almost the same as undoped system. With doping concentration, the ionic contribution to the dielectric loss as observed in low-frequency region has been suppressed and the shift in relaxation frequency toward higher frequency side has also been observed. The electrical conductivity and threshold voltage have been decreased with increasing concentration of nanoparticles (NPs). The continuous increase in dielectric anisotropy with increasing the concentration of NPs has also been observed. These results have been attributed to the trapping capability of free ions by TiO2 NPs. Further, we focused on the study of photoluminescence (PL), UV absorbance and Fourier transformed infrared spectroscopy (FTIR) of pure and doped systems. The continuous increase in PL intensity without any shift in emission peak has been observed for doped systems. Enhancement in UV absorbance with increasing concentration of NPs has also been observed. The effect of NPs doping on molecular dynamics of NLC can be clearly seen by FTIR study. The results suggest that the TiO2 NP-doped weakly polar NLC can have significant improved dielectric, electro-optical and optical properties. This makes the weakly polar NLC to be a potential candidate for many applications. تفاصيل المقالة
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        2 - Silver nanoparticles dispersed in nematic liquid crystal: an impact on dielectric and electro-optical parameters
        Rohit Katiyar Kaushlendra Agrahari Govind Pathak Tripti Vimal Geeta Yadav Kamal Kumar Pandey Abhishek Kumar Misra Atul Srivastava Rajiv Manohar
        AbstractIn the present study, nematic liquid crystal (NLC) 4′-(Octyloxy)-4-biphenylcarbonitrile dispersed with three different concentrations of silver nanoparticles (Ag NPs) is characterized by electro-optical and dielectric spectroscopy method. The dispersion of Ag NP أکثر
        AbstractIn the present study, nematic liquid crystal (NLC) 4′-(Octyloxy)-4-biphenylcarbonitrile dispersed with three different concentrations of silver nanoparticles (Ag NPs) is characterized by electro-optical and dielectric spectroscopy method. The dispersion of Ag NPs into NLC material leads to the change in physical parameters such as dielectric permittivity, photoluminescence, threshold voltage, response time and splay elastic constant. The AC conductivity and threshold voltage of Ag NPs-dispersed composite system have increased significantly. The increase in the AC conductivity for the composite system is attributed to the Ag NPs-assisted induced charge transfer mechanism in the system. Moreover, the increase in AC conductivity value for Ag NPs/NLC composite system discloses its importance in photovoltaic solar cell. تفاصيل المقالة