(High Temperature Materials Division Outstanding Achievement Award) A Country Boy Finds Materials Science

Abstract

I am greatly honored to have been chosen by the High Temperature Materials Division of the Electrochemical Society to receive their Outstanding Achievement Award for 2016. For this lecture, I will give a brief review of who I am, my career in teaching, my research interests in both insulating and electrical conducting oxides and focus on what I perceive as my major contributions to the world of ceramics (high temperature materials). Ceramics are well-known for their ability to serve as electrical and thermal insulators, structural components and for corrosion protection. In addition, their unique ability to interact with electric and magnetic fields yields properties that can vary many orders of magnitude. These include the dielectric permittivity, electrical conductivity, piezoelectricity, magnetic susceptibility, and magneto-and electro-optics. With these variety of properties, the use of ceramic components is so vast that it includes most of the devices, which we encounter and use every day.For example, the electrical insulating properties allow use of materials such as alumina for substrate in integrated circuits as well as high voltage insulators (e.g. computers. spark plugs, TV). Electrical energy storage capabilities have allowed ceramic materials to be integral parts of electronic circuits. Both require active component isolation as well as local power supplies which capacitors provide (e.g. TV, computers, cell phones). High electronic conductivity allows ceramics to be used as electrodes as well as resistors for a wide range of applications. Piezoelectric properties allow ceramics to serve as transducers for many everyday applications (e.g. ultrasonic imaging and smoke detectors]. The ability of zirconia to display high oxygen conductivity has enabled a rapidly growing list of applications such as oxygen sensors (every automobile has one), oxygen separations membranes and electrolytes for solid oxide fuel cells.All of these applications of ceramics are perfect examples where understanding the structure-property relationships at multiple scale levels were a key necessity for success. Amongst the crystallographic symmetries which have yielded the most varied properties, the perovskite system reigns supreme. I have dedicated my research career to this system and explore the influence of composition and defect structure on both electrical insulating and conducting systems. I first will discuss the properties and characteristics of this unique class of ceramics which allows them to be utilized both as electrical insulators as well as electrical conductors. I will then give some examples in which the properties are tailored to meet requirements of specific applications: capacitors, solid oxide fuel cells, and sensors.