CREST: Center for Advanced Materials and Smart Structures.

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There is a keen interest in developing ceramics for a variety of applications ranging from use as structural components, to energy-efficient thermal barriers, to high- performance electronic substrates. Structural ceramics have unique properties that can be used to great advantage in advanced heat engines, such as automotive gas turbines, and low-emission high-efficiency diesel engines. Certain composites are also being developed for various high- temperature applications such as wear resistant materials and smart structure application. Smart ceramic fibers and piezoceramic patch sensors may be attached to the external surfaces of structures, or directly embedded within materials such as advanced composites, to provide in-situ measurements of composite curing, health monitoring of structures, estimating aerodynamic loads on flight vehicles, etc. Thin film oxide-based structures, including high- critical temperature superconductor (HTSC) structures and ferroelectric perovskites, are needed for fabrication of electronic devices such as various sensors and transducers, filters and nonvolatile memories. This film III-V nitrides have also generated tremendous interest because of high- brightness semiconductor light-emitting diodes (LEDs) and injection lasers with wavelengths ranging from red to ultraviolet (UV). This proposal focuses on basic science issues affecting both advanced structural ceramics and electronic ceramic materials in a synergistic manner. The research team includes North Carolina A&T State University (NC A&T), North Carolina State University (NCSU), Oak Ridge National Laboratory (ORNL), and selected industrial partners. NC A&T State University has been associated with both ORNL and NCSU for many years in the advanced ceramic materials research area, and has trained and graduated students together with these organizations. This proposal addresses the fabrication of advanced materials and smart structures using innovative materials proce ssing methods ranging from ion-assisted pulsed deposition and plasma-source molecular beam epitaxy for thin films, to liquid infiltration and reaction synthesis for bulk materials. The advanced materials and their structures of particular interest include structural (surface engineered ceramics, metal-ceramic joints, metal-ceramic composites, tungsten carbide-aluminide composites, and piezofiber composites), and electronic (high-Tc superconductor heterostructures, piezoelectric thin film structures, and wide-bandgap III-V nitride heterostructures) materials. The proposal emphasizes materials processing, characterization, structure-property correlations, performance testing, and modeling for all the proposed materials structures in a coherent way, utilizing complementary skills at NC A&T, NCSU, ORNL, and industry partners. The Center will systematically investigate the influence of various processing parameters on microstructure evolution and properties. Additionally, the atomic structure and chemistry of defects and interfaces will be investigated using high resolution TEM (with 0.18 nm point- to-point resolution) and STEM-Z contrast (with point-to- point resolution 0.13 nm) microscopy techniques. The above combination of techniques, expertise and instrumentation affords the exploration of the nature of metal-ceramic interfaces produced under pulsed laser irradiation, and of interfaces in superconductor and semiconductor heterostructures; and these will then be correlated with properties and performance of these novel materials structures. Graduate and undergraduate students will be trained under the joint supervision of NCA&T, NCSU, ORNL and industry partners. We propose to build upon existing collaborative research and education programs involving various combinations of the proposal partners (NCA&T-NCSU, NC A&T-ORNL, NCSU-ORNL, NCSU-Kopin, NCA&T-numerous industries, etc.). Strong outreach efforts targeted towards the local community will also be a pa rt of this center activity.