Electrical energy storage devices are currently the main limiting factor in many electrical devices and with the increasing demands placed on electrical power over fossil fuels, high energy density materials are essential. Previous research by Huang et al. on bulk (1-x)Bi(Zn₁/₂Ti₁/₂)O₃-xABO₃ solid solution systems led to the discovery of an...
A new group of lead free piezoelectric perovskite solid solutions, (1-x)Bi(B'B")O₃-xABO₃, were obtained via solid-state processing techniques. The solubility of unstable perovskite Bi(B'B")O₃ compounds into stable perovskite compounds was found to be related to the tolerance factor of the ABO₃ perovskite endmembers. The morphotropic phase boundary (MBP) in perovskite solid...
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...
Piezoelectric materials have been widely used in electromechanical actuators, sensors, and ultrasonic transducers. Among these materials, lead zirconate titanate Pb(Zr[subscript 1‐x]Ti[subscript x])O₃ (PZT) has been primarily investigated due to its excellent piezoelectric properties. However, environmental concerns due to the toxicity of PbO have led to investigations into alternative materials systems....
The lead-zirconate-titanate (PZT) solid solution system is currently the workhorse of piezoelectric-based microelectromechanical systems (MEMS) research. Among bulk materials it is known to be one of the strongest piezoelectrics, with extremely high piezoelectric coefficients and electro-mechanical coupling factors. Reproducing these exceptional qualities in thin film form, however, requires precise tuning...
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...
Due to the high cost of precursor materials, complex oxides of 4d and 5d transition metals are under-studied compared to their 3d counterparts. Recent studies have shown that oxides containing heavier transition metals can exhibit exotic electronic states due to presence of strong spin-orbit coupling. The goal of this dissertation...
Piezoelectric materials convert mechanical strain into a dielectric displacement, as well as the converse, allowing these materials to be used as sensors, actuators, and transducers. Currently, lead zirconate titanate (PZT) is the primary material used in these applications. Due to environmental toxicity and safety concerns associated with Pb, development 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...