Energy Efficient Magnetoelectric Materials by Ionic Approaches: Fundamentals, Challenges and Perspectives
26 Jan - 29 Jan 2020
Physikzentrum Bad Honnef
Dr. Karin Leistner, IFW Dresden • Prof. Jordi Sort Viñas, U Barcelona, Spain • Dr. Robert Kruk, Karlsruhe Institute of Technology
Control of interfacial properties plays a crucial role in many modern nanoscale devices. Ionic mechanisms for the manipulat ion of interface magnetism is an emerging topic in the field of voltage control of magnetism for low-power nanoscale devices. In comparison to other magnetoelectric approaches, magneto-ionic manipulation offers the possibility of (i) triggering non-volatile magnetic response at room -temperature and (ii) accessing materials beyond ultra-thin films (2-3 nm), as shown in seminal magnetoelectric studies in metals. A manifold of solid and solid/liquid magneto-ionic architectures have been reported within the last few years. Electrochemical mechanisms like oxygen ion migration and reduction/oxidation of transition metals or Li intercalation are proposed to tune magnetic properties (e.g., magnetization, anisotropy, coercivity, domain wall pinning, exchange bias, or spin reorientation) in materials ranging from thin film ferromagnets to bulk ferrimagnets. Clear identification of the microscopic mechanisms governing magneto-ionics still remains rather challenging and will be tackled in the seminar. One example is the coexistence of electrochemical charge transfer and capacitive charging often discussed in voltage-control of magnetism. A deeper understanding of the origin of these effects is required, especially to overcome problems related to the limited kinetics determined by ionic migration. High charging speeds, similar to those attainable in resistive switching, should be considered and made possible in the near future in magneto-ionics. The most intense research activities currently deal with the nature of the ion involved, the impact of material defects and morphology, and the transfer to high surface area materials and magnetic nanostructures at critical points. The seminar aims at providing a forum for an overview of the current understanding of ionic effects in magnetoelectric materials. Fundamental ionic mechanisms and their correlation with magnetic phenomena, utilization of the spatial resolution achieved by advanced interface-sensitive measurement techniques, and routes toward the implementation of nanodevices will be covered.
The conference language will be English. The Wilhelm and Else Heraeus-Foundation bears the cost of full-board accommodation for all participants.