Project A4:

Local confinement of switching filaments in transition metal oxides in electrical, chemical,mechanical, and thermal gradients
(since 2015)

In this project we will focus our activities on investigating the nature of the reversible I/M and M/M transition along switchable nano-filaments in single crystals of the model oxides TiO2 and SrTiO3. The experimental studies of the electrical properties, electronic and crystallographic structure as well as chemical composition of the nano-filaments have the goal to verify phase transformation processes induced via electrical and chemical gradients. These investigations will be supported by ab initio calculations in order to analyse the different steps of the transformation and to extend the "local" and "chemical" model of the I/M transition to a broad class of binary and ternary transition metal oxides.

Local confinement of switching filaments in transition metal oxides in electrical, chemical, and mechanical gradients
(2011 - 2015)

Extended defects play a major role in oxide single crystals showing valence-change-type switching. Individual exits of these dislocations can be manipulated and investigated by local conductivity atomic force microscopy. The project aims at the clarification of the interplay of electrical, chemical, and mechanical stresses on the crystallographic structure, the relaxation, and the electronic properties of exits of extended defects. These studies are being complemented by ab-initio calculations of the electronic structure of filaments of extended defects in a crystal matrix, in order to elucidate the atomistic details of the filamentary valence change switching process.

Principal investigator:

Prof. Dr. K. Szot
Peter Grünberg Institut (PGI-7)
Forschungszentrum Jülich GmbH
Phone: +49 (0)2461 61 6479

back | top | projects