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...
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...
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...
New high-K dielectric materials are critically needed as chip real-estate becomes more and more of a premium in modern electronics designs. One of the most common devices used in electronics are multilayer ceramic capacitors (MLCCs) which are subject to severe volumetric constraints. One effective means to decrease the size of...
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...
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...
Since its discovery, the anomalous dielectric behavior of CaCu₃Ti₄O₁₂ (CCTO)
has drawn a great deal of attention for many possible applications in electronic
devices. The origin of the giant dielectric constant in CCTO was explained via an
internal barrier layer capacitor model, and it has been reported that the dielectric...
The properties of (1-x)BaTiO3-xBi(Mg1/2Ti1/2)O3 (BT-BMT) ceramics were fabricated from reagent-grade ceramic powders by solid-state methods and investigated for solubility, relative permittivity, dielectric loss, polarization, and electromechanical strain. The solubility limit was found to be between x = 0.3 and 0.4. Ba-deficient samples were fabricated, corresponding to stable single-phase compositions; these...
Much recent research has focused on the development lead-free perovskite piezoelectrics as environmentally compatible alternatives to lead zirconate titanate (PZT). Two main categories of lead free perovskite piezoelectric ceramic systems were investigated as potential replacements to lead zirconate titanate (PZT) for actuator devices. First, solid solutions based on Li, Ta,...