Investigating the influence of material imperfections on the operation of future magnetic ICT devices.
micromagnetic modeling, material imperfections, magnetic ICT devices
A large amount of research is devoted to the development of future ICT devices in which the data is handled magnetically. The aim is to develop fast, non-volatile memory and logic devices with low power consumption at the 100 nanometer scale. At this space scale, inherent sample imperfections as grain boundaries, voids, fluctuations in sample thickness etc. influence the magnetic processes. This can possibly hinder the functionality of the device and needs to be understood.
In this thesis we will specifically investigate the interactions of the magnetic vortex with material imperfections. A magnetic vortex has two stable states and can thus respresent a digital bit. Consequently, studying the influence of imperfections on a magnetic vortex corresponds to studying the the stability of digital data in a future ICT devices.
The magnetic vortex can get pinned at material imperfections, hindering its motion. Energetically, this can be described by means of potential wells generated by the imperfections in which the vortex core can get trapped. By changing the excitation conditions, the energy landscape deforms leading to successive pinning and de-pinning events. In this thesis we want to study the dynamics of the magnetic energy in detail.
To this end, the thesis student will perform extensive micromagnetic simulations that characterize the local pinning potentials in terms of their depth and stiffness. Amongst others, questions to be answered are: What is the influence of the nature of the imperfections? What is the resonant behavior of the pinned vortex? How are the excitation conditions changing the pinning potential?
The numerical study will be complemented by experiments checking the validity of the numerical work.
De Sterre S1 / thuis
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