TECHNICAL: Multiferroic materials possess two or more types of orders simultaneously that couple the electric and magnetic fields, yet the magnetoelectric (ME) coupling coefficients in single phase multiferroics are extremely small, making their practical applications virtually impossible. Large efforts have been devoted to developing multiferroic composites consisting of magnetostrictive and piezoelectric phases, which could possess much larger ME coefficients than single-phase materials, yet the difficulty in controlling the microstructures of the composites severely limited their development. In this project PI will develop magnetostrictive-piezoelectric nanocomposites (MPNC) using novel nanolithography based approaches, which allows one to engineer the size, morphology, and distribution of nanoscale fillers precisely in a magnetostrictive or piezoelectric matrix. Such nanostructure engineering will enable PI to design and optimize MPNC with unusual material symmetries and dramatically enhanced ME coupling. The three research goals are to: (1) Develop novel nanocomposite processing techniques using nanoimprint lithography (NIL) and soft lithography (SL) to precisely control the size, morphology, and distributions of second-phase nanofillers in a magnetostrictive or piezoelectric matrix; the matrix will be patterned using NIL or SL, which is then used as a template to deposit second-phase fillers with designed size, morphology, and distribution; three-dimensional nanostructured composites will be processed using these techniques, focusing on materials based on TbDyFe alloys, PVDF polymers, and PZT ceramics; (2) Process MPNC with optimally designed fillers size, morphology, and distribution for unusual material symmetries and dramatically enhanced ME properties, guided by PI's theoretical modeling and simulations using energy minimization approach and homogenization theory; and (3) Characterize the microstructural phenomena and ME properties of MPNC at multiple length scales, and validate theoretical modeling and simulations. NON-TECHNICAL: The education and outreach activities are tightly integrated into research, including training graduate student in an integrated research and educational program; training undergraduate student each year through Undergraduate Research Program at University of Washington; and design a set of simple experiments underlying nanoimprinting for K-12 teachers and students to convey the key concepts of nanotechnology. Nanolithography-enabled composite processing could lead to nanostructure-designed devices and systems with optimized functionality. The integrated research, education and outreach program will stimulate scientific interests of K-12 and college students, promote public understanding on nanotechnology, and attract and train next generation of work force in the strategic important field of nanotechnology.
