Physics & Astronomy Colloquium – Fall 2019 – Jamer

Speaker: Michelle Jamer (US Naval Academy)

Title: Creating Artificial Multiferroics Using Strain-Coupling Mechanisms

Abstract: Multiferroic materials have been proposed for an array of applications due to their binary or ternary co-existing magnetic spin, electric dipole, and ferroelastic properties. While many researchers are interested in optimizing these single-phase compounds, creating a strain-coupled multiferroic to mimic two or three types of ordering is a more tunable and less expensive option for device components. In strain-coupled multiferroics, a magnetostrictive/magnetoelastic thin film is grown on a piezoelectric substrate to control the desirable multiferroic ordering. Here, the systems with magnetostrictive Galfenol, Terfenol, and Co_1-xTb_x coupled to a piezoelectric PMN-PT will be discussed. Polarized neutron reflectometry (PNR) has been used in these systems to understand the unique reversal dynamics and the effect of voltage on the magnetization. A full discussion on the reversal mechanisms will provide insight on how to best utilize this system in future devices.

Bio: Michelle E. Jamer, Ph.D. is an Assistant Professor at the United States Naval Academy and the head of the Heusler Alloy and Magnetic Materials (HAMM) Lab. Previously, she was a NRC Postdoctoral Researcher at the NIST Center for Neutron Research (NCNR). She received her Ph.D. from Northeastern University working on the unique relationship between structural and magnetic disorder in Heusler compounds. Her research interests include Heusler alloys, artificial multiferroics, and X-ray magnetic scattering techniques.

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