PROCESSING, DIELECTRIC, IMPEDANCE SPECTROSCOPY OF ELECTRONIC MATERIAL: (Pb0.92Ga0.08)(Zr0.48Ti0.52)0.98O3

Purpose of Study: The present work shows studies of some physical properties of a gallium (Ga) modified lead zirconate titanate (PbZrTi)O3 with molar ratio Zr/Ti::48/52 (i.e., near morphotropic phase boundary (MPB)) having (Pb0.92Ga0.08)(Zr0.48Ti0.52)0.98O3 (PGaZT-8) as a chemical composition. Methodology: The material was fabricated employing high-temperature mixed oxide route. Main Finding: X-ray diffraction spectra suggest a distorted perovskite structure having two phases (tetragonal and monoclinic phases) with the substitution of small amount (2 and 4 wt %) of Ga in Pb(ZrTi)O3 (PZT). However, with higher concentration of Ga (6 and 8 wt %) in PZT, the multiphase perovskite structure is converted into an orthorhombic system with few impurity phase of Ti3O5. Analysis of field emission scanning electron micrograph (FESEM) of 8 wt% Ga modified PZT (PGaZT-8) shows the uniform distribution but different dimension and shape of grains depicting high-density ceramic sample. In the dielectric studies no dielectric anomaly exists in the experimental temperature range (25-500oC) in PGaZT-8, which determines the substitution of 8 wt% Ga in PZT (in MPB region) is found responsible for the suppression or shift (towards higher temperature) of known ferroelectric phase transition of PZT. There is an enhancement of permittivity, loss factor and conductivity as Pb site of PZT is doped with Ga. Applications of study: This study is useful for the determination of the characteristics of the prepared material as a base for device fabrication. Novelty of the Study: It is a systematic study of correlation of structural properties with the physical properties. It helps to understand the relaxation and conduction mechanism of PGaZT-8 using impedance and modulus spectroscopy

Dielectric characteristics of La-modified PbTiO3 nanoceramics

The nanoceramics of lanthanum (La3+)-modified lead titanate (PbTiO3) with a general formula Pb1-yLayTi(1-y/4)O3 (y = 0.00, 0.06, 0.08, 0.10, 0.12 Lead Lanthanum Titanate (PLT)) were synthesized by a mechanothermal method. Thermal analysis of the PLT samples exhibits their nature of the reaction and thermal stability. The incorporation of La at the Pb site of lead titanate (PT) not only changes the ratios of its unit cell parameters but also reduces the grain and particle size to nanoscale. The dielectric constant of PLT is dependent on La concentration. The La concentration-dependent phase transition temperature of PbTiO3 is one of the main characteristics of the material

Structural, thermal and electrical characterization of NdLiMo2O8 electroceramics, using impedance spectroscopy

We report electrical property of a polycrystalline NdLiMo2O8 ceramics using complex impedance analysis. The material shows temperature dependent electrical relaxation phenomena. The d.c. conductivity shows typical Arrhenius behavior, when observed as a function of temperature. The a.c. conductivity is found to obey Jonscher's universal power law. The material was prepared in powder form by a standard solid-state reaction technique. Material formation and crystallinity have been confirmed by X-ray diffraction studies. Impedance measurements have been performed over a range of temperatures and frequencies. The results have been analyzed in the complex plane formalism and suitable equivalent circuits have been proposed in different regions. The role of bulk and grain boundary effect in the overall electrical conduction process is discussed with proper justification. (C) 2011 Elsevier Ltd. All rights reserved

Effect of manganese on thermal, structural and magnetic properties of lanthanum modified lead titanate nanoceramics

PbTiO3 (PT) and La/Mn modified PbTiO3 (PLMT) nanoceramics were prepared by mechanical alloying and thermal methods. A thermal analysis technique has provided some important clues and guidelines for formation of required compounds and their thermal stability. The formation of single-phase perovskite compounds was confirmed by an X-ray diffraction technique. The field emission scanning electron micrograph of the compounds shows that materials have well-defined granular morphology. La/Mn substitution at Pb/Ti sites reduces the lattice distortion, and decreases ferroelectric phase temperature of lead titanate. Room temperature P-E loop confirms the existence of ferroelectric ordering in the sample. The nonlinear M-H hysteresis loop with small magnetization revealed that a ferromagnetic property is observed in PbTiO3 clue to the substitution of Mn at Ti-sites of PbTiO3 (C) 2014 Elsevier B.V. All rights reserved