Jyoshna Rout

Structural, Dielectric, and Electrical Properties of BiFeWO6 Ceramic

A polycrystalline sample of BiFeWO6 was synthesized using a high-temperature solid-state reaction method. The formation of the single-phase compound was checked using an x-ray diffraction technique. The surface morphology recorded by scanning electron microscopy exhibited a uniform distribution of grains of different sizes on the surface of the sample. The existence of ferroelectric properties in the material was confirmed by temperature-dependent dielectric and polarization studies. The temperature and frequency dependence of the electrical properties (impedance, modulus, and conductivity) of the compound were studied using a complex-impedance spectroscopy technique. The frequency dependence of the modulus and impedance plots confirmed the presence of dielectric and conductivity relaxation processes of non-Debye type. The frequency dependence of the alternating-current (ac) conductivity obeys Jonscher’s universal power law.

Structural, Electrical, and Magnetic Properties of Mechanosynthesized (1−x)BiFeO3-xBaMnO3(0 ≤ x ≤ 0.15) Multiferroic System

The multiferroic properties of (1−x)BiFeO3-xBaMnO3 (BBFMO; xxa0=xa00.00, 0.05, 0.10, 0.15) solid solutions, prepared by a mechanosynthesis technique, have been investigated. X-ray diffraction analysis showed that all the samples crystallized in the perovskite structure. The presence of infrared absorption bands around 442xa0cm−1 and 550xa0cm−1 supports the formation of perovskite structure of the system. Scanning electron microscopy (SEM) studies of the materials at room temperature showed that the average grain size of the samples decreased gradually with increasing BaMnO3 content in the BBFMO system. Detailed studies of impedance parameters revealed that the electrical properties related to the impedance of the solid solutions were strongly dependent on temperature and frequency. Ferroelectric measurements revealed that the electric polarization was significantly enhanced with increasing BaMnO3 content in the solid solution. The room-temperature M–H curves of the samples suggested that, with increasing BaMnO3 content in the system, the magnetic coercive field decreased, thus enhancing the ferromagnetic property of the prepared solid solutions.

Effect of multiple substitutions on structural, electrical and magnetic characteristics of thermo-mechanically activated BiFeO3 ceramics

In this study we report the synthesis of (Bi0.85Sr0.15)(Fe0.85Mn0.15)O3 ceramic using the thermo-mechanical (high-energy ball-milling and heat treatment) technique. Study of basic structural parameters of the material using X-ray diffraction technique confirms the formation of a single-phase compound with rhombohedral symmetry. The high-magnification scanning electron micrograph shows the distribution and size of grains on the surface of the sample. Detailed studies of dielectric and electrical properties of the material in a wide range of temperature (25–350xa0°C) and frequency (1xa0kHz–1xa0MHz) using dielectric and complex impedance spectroscopic methods have provided many interesting results. The temperature-frequency Nyquist plots of the material exhibit the existence and magnitude of grain and grain boundary contributions to the electrical parameters at high temperatures. Study of ac conductivity suggests that the material obeys Jonscher’s universal power law. The material shows weak ferromagnetism at room temperature with saturation magnetization (2Ms) of 0.24xa0emu/gm.

Synthesis and characterization of (Bi{sub 0.5}Ba{sub 0.5}) (Fe{sub 0.5}Ti{sub 0.5}) O{sub 3} ceramic

Graphical abstract: Temperature variation of (a) dielectric constant (b) dielectric loss of the sample. - Highlights: • The high values of dielectric permittivity and low value of tangent loss. • It used for microwave applications. • The impedance and dielectric relaxation in the material is non exponential and non Debye-type. • Its ac conductivity obeys Jonscher universal power law. - Abstract: The polycrystalline sample of (Bi{sub 0.5}Ba{sub 0.5}) (Fe{sub 0.5}Ti{sub 0.5}) O{sub 3} (BF–BT) was prepared by a standard mixed oxide method. Analysis of room temperature XRD pattern and Raman/FTIR spectra of the compound does not exhibit any change in its crystal structure of BaTiO{sub 3} on addition of BiFeO{sub 3} in equal ratio. The surface morphology of the gold-plated sintered pellet sample recorded by SEM (scanning electron microscope) exhibits a uniform distribution of grains with less porosity. Detailed studies of nature and quantity of variation of dielectric constant, tangent loss, and polarization with temperature and frequency indicate the existence of ferroelectric phase transition at high-temperature. There is a low-temperature anti-ferromagnetic phase transition below 375 °C in the material. Detailed studies of electrical properties (impedance, modulus, etc.) of the material confirmed a strong correlation between micro-structure and properties.

Impedance spectroscopic characteristics of Bi2Fe2W3O15 ceramics

Bi2Fe2W3O15 was prepared in the polycrystalline form using a standard solid-state reaction technique in order to study its dielectric and electrical properties. The formation of a single-phase compound was confirmed by preliminary X-ray structural studies of the material. Studies of electrical properties (impedance, modulus and conductivity) of the compound over a wide range of temperature and frequency provide many interesting results. The impedance and modulus parameters were calculated using complex plane formalism, and suitable equivalent circuits have been proposed for different temperature and frequency regions. The nature of variation of ac conductivity with frequency at different temperatures obeys the Jonscher’s universal power law. The temperature-dependence of dc conductivity pattern follows the Arrhenius behavior.

Impedance spectroscopic characteristics of Bi 2 Fe 2 W 3 O 15 ceramics

Bi2Fe2W3O15 was prepared in the polycrystalline form using a standard solid-state reaction technique in order to study its dielectric and electrical properties. The formation of a single-phase compound was confirmed by preliminary X-ray structural studies of the material. Studies of electrical properties (impedance, modulus and conductivity) of the compound over a wide range of temperature and frequency provide many interesting results. The impedance and modulus parameters were calculated using complex plane formalism, and suitable equivalent circuits have been proposed for different temperature and frequency regions. The nature of variation of ac conductivity with frequency at different temperatures obeys the Jonscher’s universal power law. The temperature-dependence of dc conductivity pattern follows the Arrhenius behavior.

Impedance spectroscopic characteristics of Bi2

Bi2Fe2W3O15 was prepared in the polycrystalline form using a standard solid-state reaction technique in order to study its dielectric and electrical properties. The formation of a single-phase compound was confirmed by preliminary X-ray structural studies of the material. Studies of electrical properties (impedance, modulus and conductivity) of the compound over a wide range of temperature and frequency provide many interesting results. The impedance and modulus parameters were calculated using complex plane formalism, and suitable equivalent circuits have been proposed for different temperature and frequency regions. The nature of variation of ac conductivity with frequency at different temperatures obeys the Jonscher’s universal power law. The temperature-dependence of dc conductivity pattern follows the Arrhenius behavior.