S. Prasad

Dielectric Relaxation In Complex Perovskite Sm(Ni1/2Ti1/2)O3

The complex perovskite oxide Samarium nickel titenate, Sm(Ni1/2Ti1/2)O3 (SNT) is synthesized by a solid‐state reaction technique. The X‐ray diffraction of the sample at room temperature shows a monoclinic phase. The scanning micrograph of the sample shows the average grain size≈0.6μm The field dependence of dielectric response and the loss tangent of the sample are measured in a frequency range from 100Hz to 1MHz and in a temperature range from 313 K to 673 K. An analysis of the real and imaginary parts of the dielectric permittivity with frequency is performed, assuming a distribution of relaxation times as confirmed by Cole‐Cole plots. The frequency dependent electrical data are analyzed in the framework of conductivity formalism. The frequency dependent conductivity data are fitted to the universal power law. All these formalisms provided for qualitative similarities in the relaxation times.

Structural and dielectric properties of Ba2LaSbO6ceramics

The ceramic Ba 2 LaSbO 6 (BLS) is synthesized by the solid state reaction technique. The Rietveld refinement of X-ray diffraction pattern at room temperature shows Monoclinic P21/n space group symmetry with lattice parameter a = 6.0720 (0) A, b = 6.1058 (3) A, c = 8.6016 (6) A and β =89.7091 ° (8). Dielectric study of sample has been performed in the temperature range from 30 °C to 300 °C in the frequency range 50 Hz to 1.1 MHz. Dielectric relaxation peaks are observed in the imaginary part of complex permittivity of the spectra. The frequency dependence of real and imaginary parts of dielectric permittivity is analyzed using Cole-Cole model. The temperature dependent relaxation time is found to obey the Arrhenius law having activation energy 0.48 eV which indicates that the conduction mechanism in the materials may be due to polaron hopping based on electron carriers. The complex plane plots of BLS shows the presence of both grain and grain boundary effects. Conductivity spectra follow the power law.

Structural and dielectric properties of Ba2LaSbO6 ceramics

The ceramic Ba 2 LaSbO 6 (BLS) is synthesized by the solid state reaction technique. The Rietveld refinement of X-ray diffraction pattern at room temperature shows Monoclinic P21/n space group symmetry with lattice parameter a = 6.0720 (0) A, b = 6.1058 (3) A, c = 8.6016 (6) A and β =89.7091 ° (8). Dielectric study of sample has been performed in the temperature range from 30 °C to 300 °C in the frequency range 50 Hz to 1.1 MHz. Dielectric relaxation peaks are observed in the imaginary part of complex permittivity of the spectra. The frequency dependence of real and imaginary parts of dielectric permittivity is analyzed using Cole-Cole model. The temperature dependent relaxation time is found to obey the Arrhenius law having activation energy 0.48 eV which indicates that the conduction mechanism in the materials may be due to polaron hopping based on electron carriers. The complex plane plots of BLS shows the presence of both grain and grain boundary effects. Conductivity spectra follow the power law.

Structural and dielectric properties of Ba{sub 2}LaSbO{sub 6} ceramics

The ceramic Ba 2 LaSbO 6 (BLS) is synthesized by the solid state reaction technique. The Rietveld refinement of X-ray diffraction pattern at room temperature shows Monoclinic P21/n space group symmetry with lattice parameter a = 6.0720 (0) A, b = 6.1058 (3) A, c = 8.6016 (6) A and β =89.7091 ° (8). Dielectric study of sample has been performed in the temperature range from 30 °C to 300 °C in the frequency range 50 Hz to 1.1 MHz. Dielectric relaxation peaks are observed in the imaginary part of complex permittivity of the spectra. The frequency dependence of real and imaginary parts of dielectric permittivity is analyzed using Cole-Cole model. The temperature dependent relaxation time is found to obey the Arrhenius law having activation energy 0.48 eV which indicates that the conduction mechanism in the materials may be due to polaron hopping based on electron carriers. The complex plane plots of BLS shows the presence of both grain and grain boundary effects. Conductivity spectra follow the power law.

Electrical properties of complex perovskite samarium nickel titanate

The complex perovskite oxide samarium nickel titanate, Sm(Ni1/2Ti1/2)O3 (SNT) is synthesized by solid-state reaction technique. The x-ray diffraction pattern of the sample at room temperature shows monoclinic phase. The microstructure analysis of the sample is performed using scanning electron microscope. Alternating current impedance spectroscopy is used to investigate the electrical properties of SNT in a temperature range from 313 K to 673 K and in a frequency range from 100 Hz to 1 MHz. A peak is observed in the frequency dependence of imaginary part of electric modulus (M″(ω)) indicating a non-Debye type of relaxation. The relaxation peak of M″(ω) moves towards higher frequencies with the increase of temperature showing the thermally activated nature of the relaxation time. The relaxation times for M″(ω) at different temperatures are found to obey Arrhenius law with an activation energy of 0.57 eV. The scaling behaviour of M″(ω) shows that the relaxation describes the same mechanism at various temperatures. The complex impedance plane plots show that the relaxation mechanism in SNT is purely a bulk effect arising from the semiconductive grains of the sample. The frequency dependent conductivity is found to obey the power law.