Multifunctional Ferroelectric Single-crystal Architecture in Glass: Fabrication, Optical Properties, and Nanoscale Polar Order

Lehigh University, Bethlehem PA

Investigators

Abstract

NON-TECHNICAL DESCRIPTION: In 2007, a joint analysis by the R&D leaders of the world's major glass companies and academia identified 'Micro/nanopatterning and Lithography' as one of the most deserving research topic for introducing new functionalities of glass in electronic applications/nanostructuring. Accordingly, this project aims on creating ferroelectric (single) crystal-in-glass architecture (FCGA). It is a new class of material that combines the exceptional electrical, mechanical, and optical functionalities of ferroelectrics with the robustness, easy formability and low cost of glass. The FCGA seamlessly merges the passive integrated optical technology with optically active ferroelectrics structures that are selectively and locally tailored. These materials would provide multiple novel functionalities, such as micro/nano electro-mechanical transducers, sensors; electrically addressable nonlinear waveguides; etc., which will be essential for the next generation of health and environmental monitoring devices, optical communication networks, and consumer electronics. The broad impact of the project is further realized by significantly expanding the current educational programs designed for the undergraduate and pre-college students as well as the public-at-large. They include domestic and international research experience for undergraduates, ?Opto-camps? for middle school children, and collaboration with Tuskegee University - an HBCU institution. TECHNICAL DETAILS: The optimum development of FCGAs requires a fundamental understanding of (i) the controlled single crystal growth by continuous wave (CW) or femtosecond (fs) laser light under glass to paraelectric to ferroelectric transformation, (ii) the nature of ferroelectric response of small dimension crystals in a confined dielectric medium, and (iii) control of ferroelectric and crystal order on the micro and nano scale. To address these issues, a team of two PIs and a collaborator from Kyoto University are applying their combined expertise in materials synthesis, laser-controlled fabrication, ferroelectric manipulation and optical characterization to a model oxide glass system that is likely to crystallize congruently and form ferroelectric crystal by reconfiguration of local atomic structure alone with no change of composition, thus simplifying theoretical interpretation of data. The exact mechanism of single crystal growth by laser irradiation is investigated as a function of laser characteristics with supporting structural information from electron microscopy and synchrotron X-ray techniques. The ferroelectric state of confined crystals is characterized by novel spectroscopic techniques pioneered by the PIs. Time permitting, experiments are planned for establishing the concepts and viability of FCGA in an infrared transmitting chalcogenide glass system by CW laser light.