"Electromechanical coupling in ferroelectric materials has given rise to a myriad of technological applications. Through the complex domain structure of ferroelectrics materials, which are typically stiff and have low damping, can exhibit significant structural damping. The applications for a material with a relatively large Young’s modulus and the ability to damp out vibrations would be useful for structures, more specifically, aerospace structures. The dynamic mechanical properties of ferroelectrics, particularly mechanical properties while an electric field is applied, are not well understood. This is due in part to the lack of experimental methods to measure such properties. Even with recent advancements in these testing methods, there still exists a gap in the ability to measure the dynamic electromechanical response of ferroelectrics over wide ranges of temperature (in particular at low temperatures for e.g. space applications). To this end, the cryogenic broadband electromechanical spectroscopy (CBES) experimental apparatus was designed and constructed, and a particular ferroelectric material, lead zirconate titanate (PZT) was tested. The CBES is a new experimental set-up allowing for the measurement of dynamic mechanical, electrical and temperature dependent properties of materials within the cryogenic temperature region. The CBES expands the current state of the art testing abilities for ferroelectrics, allowing for the simultaneous application of dynamic electrical and mechanical loads in a space-like environment, with temperatures ranging from 34-325 K. This study will review current testing capabilities and highlight the need to test ferroelectrics in this environment. The capabilities of the novel CBES and results from cryogenic viscoelastic measurements are presented, demonstrating the temperature dependent relationship between electric properties (polarization) and the viscoelastic properties (loss tangent and dynamic Young’s modulus) of PZT. The possible future applications for the CBES are also discussed"--Abstract, page iii.
Wojnar, Charles S.
Stutts, Daniel S.
Dharani, Lokeswarappa R.
Mechanical and Aerospace Engineering
M.S. in Mechanical Engineering
Missouri University of Science and Technology
ix, 76 pages
© 2019 William Kent Hays, All rights reserved.
Thesis - Open Access
Hays, William Kent, "Dynamic electromechanical characterization of ferroelectrics at cryogenic temperatures" (2017). Masters Theses. 7848.