Berlin 2018 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 45: Ferroics and Multiferroics (joint session KFM/TT/MA)
MA 45.4: Vortrag
Donnerstag, 15. März 2018, 10:30–10:50, EMH 225
In-operando study of polarization reversal in ferroelectric thin films — •Christelle Kwamen1, Matthias Rössle2, Matthias Reinhardt1, Wolfram Leitenberger2, Flavio Zamponi2, Marin Alexe3, and Matias Bargheer1,2 — 1Helmholtz Zentrum Berlin — 2Institute of physics and astronomie, University of Potsdam — 3Department of physics, University of Warwick
The mechanisms associated with polarization reversal in ferroelectric materails are still under investigations because the microscopic dynamics are not yet fully understood. The permanent quest for energy efficient technologies drives investigations on making a ferroelectric operational under lowest switching voltage. There are many studies which investigate either the electrical signature of the switching or the structural changes of the crystal lattice associated with the switching. We present here a simultaneous study of the electrical and structural responses of a lead-zirconate-titanate-based capacitor heterostructure during charging, discharging, and polarization reversal, using time-resolved X-ray diffraction. Concomitant with the ferroelectric current peak, we observe the switching is characterized by a transient disorder evidenced by a decrease of the Bragg peak intensity. A peak width increase reveals the domain dynamics during the reversal. Our investigations show how the incomplete screening of the depolarization charges affect the piezoelectric response, measured via the Bragg peak position. We examine the interplay between charge flow, atomic motion in real time during device operation. We investigate how ultrashort laser pulse excitation can increase the charge flow in a biased device.