Charles Deering McCormick Professor of Teaching Excellence

BS, Ceramic Science, Pennsylvania State University

PhD, Materials Science and Engineering Massachusetts Institute of Technology

Contact Info

 

 

Structure-Property Relationships in Electroceramics

    Our group investigates fundamental structure-property relationships in important electroceramics, including transparent conducting oxides (TCOs), ferroelectric oxides, mixed ionic/electronic conductors (fuel cell electrodes/electrolytes), and electrocomposites. We also have an extensive program in chemically bonded (cement-based) ceramics. We are developing new TCO compounds and solid solutions by investigating phase space (ternary systems) and by characterizing the defect chemistry of these phases. These materials serve as transparent electrodes in applications such as solar cells.
    Interfacial phenomena play a crucial role in the electrical properties of grain boundary controlled electroceramics, including ferroelectric ceramics. We employ AC impedance spectroscopy (AC-IS) to study size effects (grain size, film thickness) in electroceramic bulk and thin film materials. Our effort combines AC-IS measurements of bulk ceramics and thin film ceramics with pixel-based computer modeling of electrical property-structure relationships.
    An emerging application of impedance spectroscopy is for the characterization of electrocomposites, including fiber-reinforced composites (FRCs). We have determined that the DC conductivity and the AC conductivity respond differently to the presence of highly conductive particles or fibers in FRCs, making IS a powerful tool for microstructural characterization.

   Our group is also active in the area of nanoscale materials science. Nanoceramics are being developed for more efficient low temperature solid oxide fuel cells. We reported the first AC-IS data for carbon nanotube cement matrix composites. We are also active in the National Center for Learning and Teaching devoted to nanoscale science and engineering education.

   Mason group research is supported by the National Science Foundation, the Department of Energy, and the Center for Advanced Cement-Based Materials..

More on Prof. Mason's research.

 

Associations and Awards

Member, International Academy of Ceramics

Charles Deering McCormick Professor of Teaching Excellence

Fellow, ACerS

Fulrath-Pacific Award, ACerS, 1994

Schwartzwalder-PACE Award, ACerS, 1990

 

Recent Publications

"Impedance/Dielectric Spectroscopy of Electroceramics. Part 1: Evaluation of Composite Models for Polycrystalline Ceramics,” N. J. Kidner, Z. J. Homrighaus, B. J. Ingram, T. O. Mason, and E. J. Garboczi, J. Electroceram., 14, 283 (2005).

“Characterization of Fiber Dispersion in Cement Composites Using AC-Impedance Spectroscopy,” L. Y. Woo, S. Wansom, N. Ozyurt, B. Mu, S. P. Shah, and T. O. Mason, Cem. Concr. Comp., 27, 627 (2005).

“Chemical and Structural Factors Governing Transparent Conductivity in Oxides,” B. J. Ingram, G. B. Gonzalez, D. R. Kammler, M. I. Bertoni, and T. O. Mason,” J. Electroceram., 13, 167 (2004).