On Thursday, the 26th Of October 2017 at 14h00, Marine SCHOTT from UGA/Neel Institute, will defend her PhD thesis entitled “Electric field control of magnetic properties of Pt/Co/AlOx system”
Place : Amphithéâtre du CNRS / building A – 3rd floor – 25 rue des Martyrs, Grenoble
During my PhD, we chose to study the particular effects that are linked to the electric charge accumulation in the nano-magnet. This effect, also known as the electric field effect, was studied on the different magnetic properties of our films. They were probed by magneto-transport and magneto-optical measurements. These measurements were conducted on asymmetric Pt/Co/AlOx trilayers. These structures were sputter-deposited on a wedge shape for the alumina. This leads to a nanometric control of the oxidation degree of the interface. Then, a wide range of magnetic parameters is available on a unique sample. Systematic characterization of these structures showed an interesting zone for magnetic properties (spontaneous stripe domains linked to a strong Dzyaloshinskii-Moriya interaction, skyrmionic bubbles). The observation of this type of magnetic object is directly linked to the weak Curie temperature (Tc) of this zone (close to room temperature). Skyrmionic bubbles are subject to lots of international studies. They are potentially attractive for memories or logic devices development. The key result of this PhD was to show the strong dependence of magnetic skymionic bubbles with electric field application. The full electrical
switch of these objects has been achieved, due to the strong electrical control of the different magnetic properties. These electric-field assisted magnetisation reversal/skyrmionic bubbles nucleation studies were performed at room temperature, which is compatible with applications.