Argonne National Laboratory

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Diffuse Scattering and Local Order in PMN-xPT

Materials Science Seminar
Matthew Krogstad, Northern Illinois University
January 9, 2018 11:00AM to 12:00PM
Building 223, Room S105

Abstract: Relaxor ferroelectrics possess intriguing electromechanical and dielectric properties, and while the physics underneath these properties remain unresolved, they are thought to be related to locally correlated atomic displacements from long-range symmetry. Single-crystal diffuse scattering provides a powerful tool to investigate such deviations from average structure, and developments in instrumentation and techniques using both X-rays and neutrons have allowed such measurements to be made much more efficiently than previously feasible.

Employing such measurements on the canonical relaxor system PMN-xPT over a range of concentrations and temperatures shows a rich array of different forms of short-range correlations. By tracking these different forms across the phase diagram and using the contrast between X-ray and neutron scattering data, it is possible to connect them to the various bulk properties displayed by PMN-xPT, offering valuable insight into the microscopic origins of its intriguing properties.