- Professor of Materials Science and Engineering
- Director, Center for Dielectrics and Piezoelectrics (CDP)
Professor Randall received his B.S. degree in Physics at the University of East Anglia (United-Kingdom). He then performed his graduate studies at the University of Essex in Experimental Physics. He then performed post doctoral studies at Pennsylvania State University. He later entered the faculty of Material Science and Engineering in 1994 as an associate professor and become Full professor in 1999. In 1997, he became the Director of the National Science Foundation’s Center for Dielectric Studies at the Pennsylvania State University. He has had a number of visiting positions during his career including Shonan Institite (Japan), EPFL (Switzerland), and University of Sheffield (United Kingdom). In a sabbatical year (2004-2005) he was a Visiting Fellow at Fitzwilliam College, at Cambridge University. He was named Fellow of the American Ceramic Society in 2004. In 2006, he was elected as an Academician to the World’s Congress of Ceramics. He has published over 200 papers and holds 11 patents.
Professor Randall utilizes a combination of the material science approaches of structural-property-process-performance relations and coupling these with material physics to understand and design future generation electroceramic materials and devices. Specific materials the group is studying are ferroelectric and related materials, microwave, and piezoelectric materials in a variety of different forms, ranging from crystal structure, composition, particle and grain size, bulk, film and composites are considered.
Our philosophy is to use extreme application needs to direct a fundamental study to enable material advances to be made and implemented. These extreme performance parameters include a combination of temperature, electric field strength, frequency- time and size reduction. Under these conditions, we are concerned with basic mechanisms that control the degradation under all times of use. These time dependant failure mechanisms may be controlled through important physical processes such as electron injection at an electrode or grain boundary, oxygen vacancy migration, defect dipole rotations, thermochemical and electrochemical reactions at interfaces. Any of these or similar phenomena are built into a material through the fabrication thermal processes and remain in a metastable state, but ultimately these defects drive the degradation mechanisms and thereby prevent the implementation of new materials into a system. Once understanding the sources and failure processes, our group develops methods through process modifications or design new materials or chemistries to suppress these deleterious effects.
The above approach has proven extremely useful in the education of our students and the research conclusions have attracted collaborations with leading international electroceramic based companies.