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  1. Principles for Formation of Transversely Modulated Heterophase NanostructuresHugh A. Bruck, University of Maryland College Park, DMR 0907122 The project focuses on the development of new principles for forming transversely modulated heterophase nanostructures (TMNS) through epitaaxial self-assembly that will result in the engineering of new metallic microstructures with enhanced properties and functionality. Intellectual contributions are expected in four areas: (1) Development of principles of design for thin film materials with controlled heterophase nanostructures for tailoring of interfaces at the nanoscale, (2) Development of a new self-consistent, experimentally-verified model for phase transformations under epitaxial control, (3) Development of new techniques for processing TMNS metallic thin films, (4) Development of new methods for characterizing TMNS to provide fundamental insight into the relationship between the cooperative behavior of the nanostructure and the mechanical properties of metallic thin films In our previous NSF project, we modeled and fabricated TMNS in multiferroic oxide systems (see figure). We are currently demonstrating the formation of TMNS in metals using NiTi alloys and AgSi eutectic systems on a single-crystal Si substrate. Mathematical models are also under development for predicting the microstructures that will form in these binary metallic systems. Schematic of principles for formation of TMNS in metals: (1) from crystalline film, (2) from amorphous film Multiferroic Oxide TMNS: Cross-section TEM (a), high resolution cross-section TEM (b), plan-view TEM (c) and phase-field modeling (d) images showing CoFe2O4 pillars embedded in PbTiO3 matrix

  2. Principles for Formation of Transversely Modulated Heterophase NanostructuresHugh A. Bruck, University of Maryland College Park, DMR 0907122 From the new method of for materials design developed here, there are three directions of possible practical applications of TMNS: (1) modification of physical properties, (2) tailoring of interfacial properties, and (3) formation of non-equilibrium structures that are not possible in bulk materials or uniform epilayers. These will impact the development of new structural and functional multiphase nanomaterials for a wide spectrum of applications, such as sensors, actuators, magnetic recording media, wear resistant coatings, high temperature or corrosion resistant structural materials, and thermoelectric devices. The creation of such self-assembled modulated structures in epitaxial films can lead to a new class of macroscopic composite materials consisting of alternating passive and transformable layers with self- assembling nanostructures. Impacts are also expected in the following educational and societal areas: (1) strengthening the practical knowledge and experience of students who will serve as future researchers in the design of nanostructured materials with a new course, “Materials by Design at the Nanoscale”, and (2) a coupled theoretical and experimental approach to research and education that ensures broad access to the knowledge needed to enhance the interest and skills of future engineers and researchers using sputtering techniques, nanoindentation, and computational materials science. Circular Example of a functional NiTi film with transversely modulated heterophase nanostructures that can be used for recording media