C8 Study of localized defects in phase change materials and oxides with atom probe tomography and correlative microscopy

In project C8 (2019-2023) we will explore the structural, electrical, and chemical properties at the nanoscale of various valence-change and phase-change materials by means of the combination of atom probe tomography with transmission electron microscopy and electron-beam induced current. We will detect chemical inhomogeneities at the sub-nanometer level and in three dimensions and will analyze the role of defects for the bonding properties which may differ substantially from conventional bonding mechanisms such as metallic, ionic and covalent bonding to the recently developed conjecture, namely metavalent bonding as a novel bonding mechanism. Moreover, crystalline phase change materials contain a high density of structural defects. For the different material and device concepts explored within the SFB, including Mott-type oxides and superlattice layers in interfacial phase-change materials, the project will provide deep insights into the role of chemistry and structural changes for the switching processes and its kinetics.

Principal investigator:

Dr. Oana Cojocaru-Mirédin
I. Physikalisches Institut IA
RWTH Aachen University
Phone: +49 (0)241 80 20270
E-mail: cojocaru-miredin@physik.rwth-aachen.de