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Nanocrystalline pure and erbium (Er3+)-substituted bismuth ferrite nanoparticles were synthesized by the citrate-gel auto-combustion method. Prepared powders were sintered at 500 °C for five hours in the air and characterized by XRD, TEM, and HR-TEM. X-ray diffraction (XRD) analysis showed the distorted rhombohedral structure of the ferrites. The surface morphology and particle size of the samples were observed by high-resolution transmission electron microscopy. The lattice parameter, crystalline size, X-ray density has been calculated from d-spacing. The perceived results can be explained depending on doping concentration. The temperature dependence of magnetic properties of Bi-Er nanoparticles was carried out by using a vibrating sample magnetometer (VSM). The magnetization as a function of applied field at ± 100 Oe was carried out at 3 and 300 K. Zero-field-cooled and (ZFC) and field-cooled (FC) magnetization measurements under an applied field of 100 Oe in the temperature range of 3-360 K. These measurements give the results of blocking temperature (Tb) at around 350 K. [ABSTRACT FROM AUTHOR]

The bismuth layer structured ferroelectric (BLSF) ceramics consisting of four-layers (BaLa0.75Bi3.25Ti4O15) and five-layers (Ba2La0.75Bi3.25Ti5O18) were prepared by the conventional solid-state reaction method. Summerfield ac-conductivity scaling analysis was used to evaluate the electrical behavior and the ac-conductivity isotherm curves. The relaxation results were corroborated with the Raman Peak positions and full width at half maximum was obtained by using Lorentzian peak fit method. Finally, the results were compared with the two-layered relaxor-compound (Bi2.45La0.55TiNbO9) and technologically standard three-layered compounds (La0.75Bi3.25Ti3O12; BLT). The dielectric relaxation of Bi2.45La0.55TiNbO9was verified using modified Curie-Weiss law and Vögel-Fulcher relationship. An attempt is made to realize the typical collective nature of the ionic conductivity of the samples. [ABSTRACT FROM AUTHOR]

Nano particulate Barium Bismuth Titanate (BaBixTi1-xO3-δ) materials with (x = 0.25, 0.075. 0.125 and 0.175) were prepared through sol-gel chemical route (Pichini method) and the XRD patterns were indexed on the basis of tetragonal-BaTiO3 phase. The electrical impedance measurements were carried out on the samples by using Auto Lab PGSTAT30 impedance analyzer in the frequency region 100 Hz-1 MHz from RT to 500°C. Impedance spectroscopic and complex explicit plots show the presence of both bulk and grain boundary effects, and impedance spectroscopy is shown to be an efficient method capable of detecting the conductivity species and estimating the electrical conductivity as well as activation energy value. Finally, the results are interpreted in terms of the defect dynamics and conduction mechanisms taking place in the samples. [ABSTRACT FROM AUTHOR]

A and B site modified new bismuth layered structure ferroelectric ceramics of the Aurivillius family were prepared by the solid-state route. Impedance measurements were performed on these samples to understand the relaxation effects in the frequency range of 100 Hz to 1 MHz. From the detailed impedance and modulus spectroscopic analysis, it is found that the aliovalent modified B-site enhances the relaxor-like nature, compared to A-site substitution. These results were corroborated with ac-conductivity transport analysis. In this connection, a defect formula is also proposed. The results are discussed. [ABSTRACT FROM AUTHOR]