Lattice Dynamics and Phase Transitions in Nanoscale Ferroelectric Heterostructures

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Non-technical abstract:Modern science and technology of electronic materials have moved rapidly towards artificially engineered structures at nanometer (one billionth of a meter) scales. Physical behavior of materials at nanoscale is principally different from that of macroscopic materials in many aspects. The objective of this project is experimental investigation of fundamental physical properties of nanoscale ferroelectrics - an interesting and practically important class of electronic materials with high potential for applications in various devices, such as computer memories or microwave electronic devices. Shrinking dimensions down to nanometer scale demand characterization techniques capable of probing the fundamental properties of ferroelectric nanostructures. This project will utilize optical spectroscopic techniques using ultraviolet light to probe the atomic vibrations in nanoscale ferroelectric materials, which are essential for understanding their practically important properties. The experimental results to be obtained will test the validity of current theories of ferroelectrics and will contribute to a comprehensive understanding of nanoscale ferroelectricity. The proposed research will be closely integrated into the educational program at Boise State University, actively involving undergraduate and graduate students in the cutting-edge research and training, and acting as a catalyst for the effective use of the state-of-the-art optical instrumentation for educational purposes. The project will enhance Boise State's strength in the field of condensed-matter physics and materials science, which aligns perfectly with Boise State's strategic goal of becoming a metropolitan research university.Technical abstract:Ferroelectrics are a class of materials possessing a spontaneous electric polarization, which can be switched by the application of an electric field. Ferroelectrics exhibit a wide variety of interesting properties making them extremely attractive for applications in various electronic and optoelectronic devices. In recent years, the science and technology of ferroelectrics have moved rapidly towards artificially engineered thin films and multilayer structures at nanometer scales. A fundamental property of ferroelectrics is the dynamics of crystal-lattice vibrations, which is related to many of their practically important properties. This project focuses on the experimental study of lattice vibrations and phase transitions in nanoscale ferroelectrics by the novel technique of ultraviolet Raman spectroscopy. It will address several issues of major importance for understanding nanoscale ferroelectricity, such as the effects of strain and reducing size on ferroelectric behavior. The experimental results will test the validity of current theories of ferroelectrics, and will contribute to a comprehensive understanding of nanoscale ferroelectricity. The proposed research will be closely integrated into the educational program at Boise State University, actively involving undergraduate and graduate students in research and training and acting as a catalyst for the effective use of the state-of-the-art optical instrumentation for educational purposes.