Structural and Dielectrical Properties of Nb-doped PZTN Ceramics

Pradeep Kumar Yadav¹, Ruby Yadav² and Sanjay Kumar Singh^3,*

 ^1,2Physics Department, Meerut College, Meerut, U.P., India.

³Directorate of Higher Education, U.P., Pryagraj, India.

*email: tanishqrawal@gmail.com

Polycrystalline samples of PZTN with the compositions Pb_1.1-x/2 (Zr_0.53 Ti_0.47)_1-x Nb_xO₃ (where x=0.00, 0.01, 0.02, 0.03, 0.04, and 0.05) has been prepared by solid state reaction method. X-ray diffraction studies suggest that the compounds are in rhombohedral phase. Pyrochlore value and surface morphology was studied by scanning electron microscope (SEM). Detailed studies of dielectric constants as a function of temperature (40^oC-500°C) and frequency (100Hz-1MHz) suggest that the compound do not have relaxor behavior and undergoes diffuse type of phase transition.

Keywords:   Dielectric, ceramics, XRD, SEM.

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The study of Magnetoresistivity in 10% Ag dopped HTS Bi₂Sr₂ CaCu₂O_x

Dr. Pawan Kumar

Associate Prof., Department of  Physics, A.S. (P.G.) College,Sikandrabad, U.P., India.

The Magnetoresistance of 10% Ag dopped Bi- Sr- Ca- Cu-O system within its superconducting transition region was studied. In low magnetic fields the square of Magnetoresistance was found to show a linear dependance of H. The results have been explained in terms of randomly diluted Josephson junction present in the sample.

Keywords: Magnetoresistance, Hall geometry, Superconductivity.

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Nanocomposite Copolymer of 1-(2-aminophenyl) Pyrrole and 2-3-dimethyl Aniline Synthesis and Characterization

Ajay Chauhan¹, Rajeev Rathore²* and Vaibhav Jain³

¹Physics Department, Meerut College, Meerut, U.P., India

²Chemistry Department, Meerut College, Meerut, U.P., India

³Physics Department, DAV (PG) College, Bulandshahr, U.P., India

^*email: r.rathore_@hotmail.com

Nanocomposites of copolymer of 1-(2-aminophenyl) pyrrole and 2-3-dimethyl aniline is synthesized using chemical oxidative polymerization doped with HCl and Ammonium persulfate (APS) used as an oxidant. Nanocomposite copolymer obtained is characterized for physical and structural configurations by UV-Vis., FTIR spectrophotometer and XRD. TGA for thermal stability and 4-probe method is used to determine the electrical conductivity. Spectral study confirms the p-p* transition in nanocomposite copolymer. The formation of copolymer and its structure is confirmed by FTIR. The amorphous nature of polymer nanocomposite is established by the XRD. The electrical conductivity of sample was comparable to the intrinsic conductive polymers used. SEM micrographs are used to estimate the size and surface morphology.

Key words:   Nanocomposite, Copolymer, SEM, FTIR, XRD.

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Electrical and Thermoelectric Properties of NaAlO₂

¹Shivendu Tripathi and ²Subodh Kumar Sharma

¹Satish Chandra College, Ballia, U.P., India.

²S. S. V. College, Hapur, U.P., India.

The electrical conductivity (σ) with ionic (σ_i) and electronic (σ_e) conductivity and thermoelectric power (S) of NaAlO₂ have been separated over the entire temperature range from 450K to just below its melting point with the help of time dependent study of dc electrical conductivity. Superionic phase has been observed well below the melting point in which the conductivity is almost purely ionic. The phase transition temperature below which the solid transform from superionic to normal phase has been obtained from electrical conductivity (σ) and thermoelectric power (S) measurement. In normal ionic phase, the solid NaAlO₂ shows mixed conduction (ionic and electronic) behavior. The variation of σ_i and σ_e with temperatures has been shown in various plots and the conduction mechanism is explained by extended lattice gas model.

Keywords: Ionic conductivity; Electronic conductivity; Thermoelectric power, Phase Transition temperature.

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Physicochemical Characteristics of Groundwater in Different Sites of Agra City, Uttar Pradesh

Vinod Kumar¹ and Smita Chaturvedi²

^1,2Department of chemistry, Agra College, Agra, U.P., India.

¹Email: vinodkchem@gmail.com

A systematic study has been carried out to evaluate the physico-chemical characteristics of groundwater in Agra city. Six groundwater samples were collected from various locations during February 2018 to March 2018 and analysed for pH, turbidity, electrical conductivity, total dissolved solids, total alkalinity, total hardness, calcium, magnesium, fluoride and chloride following the standard methods and procedures. Present work revealed that groundwater is comparatively very hard and slightly alkaline. Fluoride contents vary from place to place. The sampling sites showed that the physico-chemical parameters were not within the water quality standard and was not found fit for drinking.

Keywords: Physico-chemical Characteristics, Groundwater in Agra city.

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