2016-Sustainable Industrial Processing Summit
SIPS 2016 Volume 7: Yang Intl. Symp. / Multiscale Material Mechanics
| Editors: | Kongoli F, Aifantis E, Wang H, Zhu T |
| Publisher: | Flogen Star OUTREACH |
| Publication Year: | 2016 |
| Pages: | 190 pages |
| ISBN: | 978-1-987820-48-5 |
| ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
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Voltage-driven magnetization switching by charge-mediated magnetoelectric coupling
Min Yi1; Bai-Xiang Xu1;1TECHNICAL UNIVERSITY OF DARMSTADT, Darmstadt, Germany (Deutschland);
Type of Paper: Regular
Id Paper: 410
Topic: 1
Abstract:
Currently, magnetic field or spin torques generated by power-dissipating currents are often used for the magnetization switching in spintronic devices. In order to revolutionize the spintronic devices for low-power consumption, fast response, low loss, and device minimization, the magnetization switching purely with a voltage via the magnetoelectric (ME) coupling has been proposed. Many efforts have been made on the switching via ME coupling induced by the piezoelectric strain. Intrinsically, this is a strain-assisted switching process. However, in thin film multiferroic heterostructures, the strain-mediated ME coupling is often limited due to the substrate clamping effect. In this talk, we demonstrate the charge-mediated ME coupling for voltage-driven magnetization switching in nanomagnets via a multiscale study combining first-principles calculations and magnetization dynamics. We focus on the ME coupling in metal-magnet-insulator nanoheterostructures. Taking the Pt-FePt-MgO nanoheterostructure as a model system where FePt is an attractive magnet for memory and logic devices, we firstly apply first-principles calculations to determine the relationship between magnetic anisotropy energy (MAE) and the electric field (E). MAE change of the system is shown to be attributed to the electric field induced charge in the FePt-MgO interface. The dependence of the MAE-E relationship on the layer number of FePt and the lattice variation of the system is also studied. Then the MAE-E relationship is input to the magnetization dynamics analysis of a single-domain FePt nanomagnet in the shape of an elliptical cylinder. The switching dynamics are studied in terms of different ramp rates, pulse widths, amplitudes of the voltage, in order to find the conditions for a fast and deterministic 180 degree switching. Finally, the voltage-driven magnetization switching at finite temperature is considered.