Materials today enable engineers to devise, design and build systems, extending their performance, capabilities and impact on Society.  There are also many potential technologies that have not taken off yet because of a lack of materials that have the property performances to make them economically viable.  This is particularly so in the energy conversion and sustainability areas. The activities in our newly established group are directed at the training of graduate and undergraduate students to perform innovative research that extends the capabilities of existing engineering systems through advances in materials as well as the discovery and development of materials with improved performance that can help make new materials applications viable.  Our emphasis is on oxide and related materials. And, we draw on many different areas of materials science based on fundamentals of applied physics, crystal chemistry, mechanics and materials processing.

High temperature materials. Because gas turbine engines generate a large proportion of the world’s electricity and power the vast majority of airplanes, even small improvements in the efficiency of turbines by increasing their operating temperature can dwarf advances in many other areas of materials for energy.  We have chosen to carry out research in several aspects of the behavior of the hot-section components of turbine, the blades and vanes. One is the discovery of alternative oxides for thermal barrier coatings that have even lower thermal conductivity than the currently used yttria-stabilized zirconia. Part of the challenge is to develop physically based insights that can be used to identify from the tens of thousands of oxide known to exist, candidate materials for detailed study. Another crucial area is the improvement in high temperature properties of alloys used to provide oxidation protection to single crystal turbine blades. This necessitates detailed understanding and characterization of the mechanisms responsible for high-temperature oxidation as well as the origin of morphological instabilities that occur on thermal cycling. Yet another important aspect is the microstructural design of coatings to limit radiative heat transfer from hot engine gases to the turbine alloys, which again limits engine efficiency.

Luminescent materials and sensors. One of the attractions of luminescent materials is that their luminescence carries detailed information about the state of the material, ranging from the local atomic and electronic environment to the state of stress. We currently have two long-term goals: developing new luminescent materials and their use in non-contact, high resolution measurement of strain and temperature. Strain affects the luminescence wavelength through one of the piezospectroscopic effects and temperature affects the luminescence lifetime by altering the probabilities of non-radiative and radiative emissions. We are also investigating use of luminescence in developing sensors that can provide information on the detailed exposure that a material has seen as a function of time and temperature – in essence a history sensor.

Complex oxides. Underlying much of our research is an understanding of atomic and electronic structure and how they influence the fundamental response of complex oxides to a variety of thermal, optical, magnetic and electrical stimuli. Why oxides ?  In contrast to many other classes of materials, oxides can have greater complexity in structure and also much less is known about them. Consequently they present greater opportunities for discovery. In addition, we are interested in higher level complexity, exploring the behavior of three and four phase oxide composites, particularly near different percolation thresholds, rather than the traditional two-phase composites.  For this we also need to develop, new processing techniques to fabricate fully dense nanosized, polyphase oxides.