PhD - Leuven | More than two weeks ago
is a novel field of electronics that uses the spin of electrons or the
magnetization of thin magnetic films instead of the charge for memory, computation
or sensor applications. Most of these device concepts are based on the
magnetization control by electrical currents, such as spin-transfer torque or
spin-orbit torque. The magnetization state is then determined either via
magnetoresistance or the inverse spin-Hall effects. However, these reading
mechanisms are based on electrical currents and are typically not energy
efficient. To improve the read performance, the current resistance-based scheme
needs to be replaced by a mechanism that generates a direct electrical signal.
In particular, voltage-based schemes using magnetoelectric materials and
compounds appear promising.
effects occur naturally in multiferroic materials but also in composite
materials consisting of piezoelectric and magnetostrictive layers. In such
composites, strong strain-induced magnetoelectric coupling can be observed. The
coupling can be described by effective magnetoelastic fields that are generated
in the magnetostrictive ferromagnetic layer(s) via application of stress due to
the inverse magnetostriction (Villari) effect. The stress itself can be
generated by an electric field applied across the piezoelectric layer(s). An
inverse magnetoelectric effect also exists, which generates a voltage due to
magnetization switching. The application of both the direct and the inverse
effects in spintronic devices requires the detailed understanding and control
of the direct and inverse magnetoelectric coupling in different geometries and
different material systems.
focus of the thesis is to investigate the potential to generate large voltage
signals by the inverse magnetoelectric effect based on piezoelectricity and the
magnetization switching and interaction with magnetic domain walls in
nanomagnets. The study will include the patterning
and the characterization of relevant materials on the nanoscale as well as the
design, fabrication, and characterization of suitable devices. The work will be
done in close collaboration with device engineers at imec working on magnetic
memory and logic devices.
A background in (applied) physics, or nanotechnology is ideal, together with an interest in advanced spintronic applications and current topics in magnetism as well as enthusiasm for leading edge materials.
Required background: Physics, Applied physics, Nanotechnology, Electrical Engineering
Type of work: 70% experimental, 20% modeling, 10% literature study
Supervisor: Bart Soree
Co-supervisor: Florin Ciubotaru
Daily advisor: Florin Ciubotaru, Christoph Adelmann
The reference code for this position is 2024-019. Mention this reference code on your application form.