Tricking 'old' materials to offer new properties has been a tradition in materials science and engineering innovations. It is recognized that completely new functionalities may be stabilized at the nanometer-thick wall between two different domains of the same material. These domain walls can be written, moved, broadened, and erased by external stimuli. Thus, they present an exciting opportunity to investigate new low-dimensional physics that is otherwise inaccessible. They can also be used as an active element in a new technology leveraging the functionality, mobility, and truly nanoscale thickness of the walls to achieve much higher device density and lower energy consumption. This project explores the scientific foundations of domain wall technology by understanding and exploiting novel physics and functionalities of ferroic domain walls in oxide materials. Since domain walls exist ubiquitously in nature, a full understanding of their static and dynamic properties benefits our society by broadly impacting existing fields such as ferroelectricity, magnetism, shape memory alloys, and even seismology. The educational objective of this proposal is to build a program to broaden the impact of nanoscience both scientifically and societal in the San Francisco Bay area.
TECHNICAL DETAILS: Future domain-wall technology could be implemented through ferroelectric, thermoelectric, optical, chemical, magnetic and structural functionalities present at the domain walls of a wide variety of materials. At present how to manipulate the domain walls without adversely affecting the desired wall functionality is unknown. Using locally injected point defects and globally imposed strain as control stimuli, the PI will create, image, pin, liberate, move, and erase single domain walls in a one-dimensional "wall waveguide". By doing so, the PI seeks to clear some fundamental roadblocks toward a full understanding of the physics and engineering principles of functional domain walls: i) the domain wall width and mobility will be tailored, ii) the wall functionality will be modulated and exploited for applications, iii) the Landau theory will be parametrized, the discoveries will be generalized, and iv) atomic-scale interfacial physics at the wall will be elucidated. Integrated with the research efforts, the PI has a unique educational program, entitled "Nano'ed", to prepare students for careers in areas of high national interest in either academia or industry. By emphasizing the common fundamentals that nanoscience shares with established subjects of physics, chemistry and mathematics, the PI is working on the following: i) creating a series of hands-on exhibits and experiments for K-12 students in partnership with the nearby museum Lawrence Hall of Science; ii) partnering with a campus education program in developing a unique summer class series in "Nanoscale Materials Science and Engineering" for underrepresented high school students; and iii) initiating and leading nanoscience activities in the San Francisco Bay area to transfer and exchange knowledge with industry and policy-makers, thus making the benefits of fundamental science research more tangible for society in general.
