Dielectric Response in Ferroelectric MultilayersAlexei Y. Grigoriev, University of Tulsa, DMR 1057159

Polarization dynamics, piezoelectric, and dielectric properties of ferroelectric thin films can be modified by engineering new multilayer materials. In this project, the main focus is on studying polarization dynamics and dielectric properties of ferroelectric bi- and tri-layers using synchrotron x-ray diffraction and new approaches to electrical measurements of fast switching (RSI, 2011) and dielectric response. We recently found significant nonlinearities in dielectric behavior of Pb(Zr,Ti)O3 ferroelectric bilayers. A typical bilayer has the maximum observed tunability of 50% at 600 kV/cm bias E-field. Achieving high tunability in nonlinear dielectric materials is very important for application in tunable RF devices such as dielectric varactors and micro-electro-mechanical systems (MEMS).

A. Grigoriev, M. Meisami-Azad, J. McCampbell, Rev. Sci. Instrum. 82, 124704 (2011).

(top) SEM image of an FIB-milled portion of a ferroelectric bilayer sample. (bottom) Small-signal dielectric response for a bilayer ferroelectric capacitor. The measured tunability of the bilayer reaches 50%.

Involving Students in Science and TechnologyAlexei Y. Grigoriev, University of Tulsa, DMR 1057159

A new outreach program, Demonstrations in Electricity and magnetism for School Kids (DESK) has been started. An open frame demonstrational humbucker pictured here was proposed, designed, and built by undergraduate physics students.

Undergraduate students participated in summer research, which included growth and characterization of solid and polymeric ferroelectric materials.

School kids are getting involved in exploring science and engineering. We plan visits to Tulsa-area elementary schools this fall with demonstrations including the humbucker demonstration pictured above and Lego-Mindstorms robots.