Search or add a thesis

Advanced Search (Beta)
Home > Synthesis and Characterization of Polycrystalline Ferroelectric Bulk Ceramics

Synthesis and Characterization of Polycrystalline Ferroelectric Bulk Ceramics

Thesis Info

Access Option

External Link

Author

Sareecha, Nasira

Program

PhD

Institute

The Islamia University of Bahawalpur

City

Bahawalpur

Province

Punjab

Country

Pakistan

Thesis Completing Year

2017

Thesis Completion Status

Completed

Subject

Chemistry

Language

English

Link

http://prr.hec.gov.pk/jspui/bitstream/123456789/13377/1/Nasira_Sareecha_Chemistry_HSR_2017_IUB_Bahawalpur_30.11.2017.docx

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676727461139

Similar


BaTiO3 and PbTiO3 ceramics were prepared through solid state sintering reaction. The studies were attempted at the phase pure and crack free preparation and electrical investigations of BaTiO3 ceramics with Ba/Ti molar ratio (0.98 and 0.94) and PbTiO3 ceramics (1.00, 0.98 and 0.94) Pb/Ti molar ratio in the wide range of temperatures (40–700°C) at 1kHz frequency of the ceramics perhaps for the first time. Studies were attempted to find the understanding of the conduction process and useful implementation of the controlling parameters. Thermogravimetric and Differential scanning calorimetric analysis (TGA-DSC) revealed melting temperatures, weight losses and variations in the enthalpy of crystallization of the as ground powders. Ceramics with all precursor composition were perovskite (ABO3), ferroelectric materials. Cubic structures (Pm-3m) and tetragonal (P4mmm, P4mm, P4MM) crystal structures were indicated. Curie temperature (Tc) increased from120-130°C with decreasing Ba/Ti contents. With Pb and Bi doping, Curie temperature (TC) was shifted from 120 -200°C and 120 -160°C respectively. Pb/Ti contents did shift the Curie temperature. Broad dielectric constant peaks and pronounced dielectric anomalies with relaxor like behavior were observed in the paraelectric regions. Resistivity decreased with increasing temperature, all specimens showed semiconductor behavior with negative temperature coefficient of resistivity (NTCR) characteristics. Mobility of electrons increased with thermal activation due to hopping of charge carriers from one site to another. Ohmic conductivities and associated activation energies were evaluated by impedance spectroscopy. Conductivity followed Arrhenius Law with Ea values lying in the range of single ionized and doubly ionized oxygen vacancies and Pb vacancies; ionic conduction was supposed to be responsible. Well defined hysteresis P-E loops under electric fields showed ferroelectric characteristics.
Loading...
Loading...

Similar News

Loading...

Similar Articles

Loading...

Similar Article Headings

Loading...