Heavily acceptor doped Pb1.02Dx(Zr0.5Ti0.5)1-xO3 ceramics, where A is the dopant, were investigated in this research. Dopants studied included iron, magnesium and manganese at mole concentrations x ≤ 0.20. X-ray diffraction data along with scanning electron microscopy images revealed the solubility limits of these ceramics. All doped compositions exhibited a shift...
It has been well established that ferroelectric to relaxor crossover in piezoelectric ceramics exhibit promising electromechanical and dielectric properties over a wide temperature range, applying sensors and actuators transducers and such. A plethora of research has reported giant strain in various lead-free piezoelectric ceramics and attributed the reasoning to the...
This dissertation demonstrated that the electrical properties of complex oxide-based perovskite materials could be controlled through the careful modification of both material composition and structure. This was first shown through the modification of lead zirconate titanate (Pb(Zr0.52Ti0.48)O3, PZT) solid solutions with bismuth indate (BiInO3, BI) where the relative stability of...
This thesis examines the dielectric properties of two systems based on the perovskite materials
barium titanate and strontium titanate. A solid solution was created starting with these base
materials and then adding varying amounts of bismuth-zinc titanate and sodium niobate. These
compositions were calcined and sintered at temperatures determined to...
High energy density ceramic capacitors with temperature stable permittivity across -150°C to 300°C are desired for a wide variety of electronic devices. Traditional dielectrics such as barium titanate provide a high permittivity but that permittivity is strongly temperature dependent over this specified temperature range. The goal of this work is...
The aim of this research is to develop a fundamental understanding of the dominant defect species and the relevant defect equilibrium conditions for bismuth-containing perovskites to help guide the development of these materials for emerging applications. This is of paramount importance for many demanding applications, because ultimately the defect equilibria...
High performance dielectric materials are needed for high power SiC- or GaN-based electronics which combine the best features of high energy density, low dielectric loss and high reliability and for advanced high-speed and high-voltage energy storage where temperature stability plays an important role in material properties. An ideal capacitor for...
Lead zirconate titanate (PZT) is the dominant ferroelectric material in the market due to its excellent piezoelectric properties, relatively high Curie transition temperature (T[subscript C]), low cost, etc. However, because of emerging applications with requirements for high temperature (T[subscript C] > 400 °C) ferroelectrics, researchers are increasingly looking at alternative...
Relaxor characteristic of the solid solution (1-x)BaTiO₃-(x)Bi(Zn₁/₂Ti₁/₂)O₃ (BTBZT) was investigated in this research. X-ray diffraction technique and Raman spectroscopy revealed the crystal structure of BT-BZT at various compositions. For compositions with x ≤ 0.08, the solid solutions exhibited clear tetragonal symmetry and transitioned to pseudo-cubic symmetry as the content of...
Dielectric ceramics designed for capacitor applications for use in extreme environments, such as high temperatures, high voltages, or high-pressure environments, are in great demand. Existing capacitor technology fails to perform within these extreme conditions or such environments. The development of new dielectric ceramic materials for high temperature capacitor applications is...