The behavior of materials at ever smaller length scales promises remarkably rich new vistas for basic science and technology in the coming decades, and it has stimulated the worldwide intensive competition in nanotechnology research. Exploration and understanding of the new mesoscopic phenomena to be found at small scales requires radical innovations in experimental techniques and conceptual understanding. This project will investigate a remarkably accessible new mesoscopic system - shaped superconducting mesocrystals, which exhibits a wide range of small scale phenomena that reflects general mesoscopic behavior. Superconducting mesocrystals enable comprehensive studies of few body thermodynamics and statistical mechanics, the evolution of complex mesoscopic patterns with particle number, melting of mesoscopic clusters of particles, disorder and relaxation in mesoscopic systems, and the transition from mesoscopic to bulk behavior. In addition to these general mesoscopic phenomena, these mesocrystals reveal new superconducting phenomena at small scales which contrast dramatically with conventional bulk behavior. Superconducting mesocrystal behavior is both complex and collective, and defies the conventional principles of bulk materials systems. This project supports the training of graduate students, enhancing their academic knowledge and improving their likelihood to succeed in future careers in academia, industry, or government.
This project will study shaped superconducting mesocrystals, which exhibits a wide range of small scale phenomena that reflects general mesoscopic behavior and enable comprehensive studies of few body thermodynamics and statistical mechanics, the evolution of complex mesoscopic patterns with particle number, melting of mesoscopic clusters of particles, disorder and relaxation in mesoscopic systems, and the transition from mesoscopic to bulk behavior. The mesoscopic particle that will be explored is the Abrikosov vortex which can be easily induced in superconducting mesocrystals with an applied magnetic field. A controlled number of vortices from zero to several hundred or more can be placed on a few-micron size crystal by adjusting the magnetic field strength. New mesoscopic instrumentation based on micro-electromechanical systems (MEMS) technology will be developed and/or used to allow thermodynamic measurement of the mesoscopic samples. The superconducting mesocrystals include type-I superconductor Pb with novel shapes such as icosahedron, decahedron, hexagon and triangle and type-II superconductor NbSe2 with hexagonal shape. Graduate students will carry out the experimental work. Thus, this project contributes directly to the training of the future workforce and to the national competitiveness in the important area of nanotechnology.
