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CAREER: Ferroelectric Multilayers, Superlattices, and Compositionally Graded Films DMR-0132918 PI: S. Pamir Alpay Department of Materials Science and Engineering, University of Connecticut.
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CAREER: Ferroelectric Multilayers, Superlattices, and Compositionally Graded FilmsDMR-0132918 PI: S. Pamir Alpay Department of Materials Science and Engineering, University of Connecticut Figure 1: a) and b) Schematic diagrams showing bending of a polarization graded ferroelectric plate. The gradient of self-strain results in a radius of curvature and a dome-shaped bending with a displacement of d. c) Geometrical dimensions of the graded piezoelectric structure used our the calculations. d) Physical displacement relative to the static deformation caused by the compositionally induced strain gradient, ΔD, as a function of external electric field for PbTiO3–Pb(Zr0.4Ti0.6)O3 (PT-PZT60/40), PbTiO3–Pb(Zr0.2Ti0.8)O3 (PT-PZT80/20), and BaTiO3–Ba0.75Sr0.25TiO3 (BT-BST75/25). The potential applications of compositionally graded ferroelectrics (FEs) as high performance sensors and actuators were theoretically investigated. A static bending can be expected in graded FE plates, forming a vertical displacement (Figure 1a-c). Numerical results (Figure 1d) show a high dynamic response of the displacement under an external electric field, yielding as much as ~23% strain at 50 kV/cm in PbTiO3-Pb0.6Zr0.4TiO3, comparable to large displacement actuators formed from ceramic/ceramic and ceramic/metal multilayer meso-materials like RAINBOW TM and THUNDER TM ceramics.
CAREER: Ferroelectric Multilayers, Superlattices, and Compositionally Graded FilmsDMR-0132918 PI: S. Pamir Alpay Department of Materials Science and Engineering, University of Connecticut Education: During the past three years, 9 undergraduate students (Mr. Dean Halter, Mr. Scott Virkler, Mr. Michael White, Ms. Sofia Iddir, Ms. Elisabeth Jordan, Mr. Robin Young, Mr. Kevin Rankin, Ms. Zoe Weber, Ms. Sarah Winiarz) and 6 graduate students [Mr. G. Akcay, Mr. B. Allimi, Dr. (Mr.) Z.-G. Ban*#, Dr. (Mr.) I.B. Misirlioglu*, A. Sharma, and Mr. S. Zhong*] contributed to this program. Dr. Ban is currently employed by KennaMetal Inc., PA as a research scientist after a brief stay at Argonne National Labs. Mr. Sharma graduated with an M.S. degree in April 2004 and is pursuing a career in business management. Mr. Zhong graduated with an M.S. degree in July 2005 and is continuing his work towards a PhD degree. Dr. Misirlioglu won the prestigious Alexander von Humbolt fellowship and is currently working at the Max Planck Institute in Halle, Germany. Outreach: A popular science web site on the science and technology of thin film materials was developed and uploaded thanks to the efforts of Mr. Halter, Mr. White, Mr. Virkler, and Ms. Weber. They have worked not only on the design of the web pages but on the content as well. http://www.ims.uconn.edu/~alpay/thinfilms/index.htm * Outstanding Graduate Student award by the Department of Materials Science and Engineering of the University of Connecticut, Ban (2003), Misirlioglu (20050, Zhong (2006), # Outstanding Ph.D. Thesis Award, School of Engineering, University of Connecticut