Two dimentional electron gases at oxide interfaces: the role of oxygen vacancies

Datum

03.02.2014

Zeit

15:00 - 16:00

Sprecher

Dr. Fabio Miletto Granozio

Zugehörigkeit

University of Naples

Sprache

en

Hauptthema

Materialien

Andere Themen

Materialien, Physik

Host

Christine Malbrich

Beschreibung

Abstract: Oxide interfaces exhibit functionalities that appear sometimes as a combination of those of their single building blocks, and emerge sometimes, instead, as totally new with respect to both the constituent materials. A prototypical example of this emergent behaviour is provided by the 2-dimensional electron gas (2DEG) found at the LaAlO3/SrTiO3 interface. In the work, the properties of the 2DEGs at the LaAlO3/SrTiO3, LaGaO3/SrTiO3 and NdGaO3/SrTiO3 interfaces are addressed and compared. Interfaces based on the respective amorphous counterparts are also investigated. While the formation of the 2DEG in crystalline samples is attributed to the electronic reconstruction mechanism, conductivity in amorphous interfaces is attributed to the presence of oxygen vacancies. A number of experiments have been designed and performed with the specific aim of highlighting similarities and differences of the two systems. The investigated crystalline interfaces (LaAlO3/SrTiO3, LaGaO3/SrTiO3 and NdGaO3/SrTiO3) exhibit a remarkably similar response under the application of our diversified set of investigation tools. When compared with crystalline samples, the amorphous counterparts also show a number of non-trivial similarities that can’t be directly attributed to the properties of STO. Specific experiments highlight nevertheless the different origin of carriers in the two systems. Our results allow to drive some tentative conclusions about similarities and differences of the band diagrams in amorphous and crystalline interfaces.

Links

• Seminars at the IFW

Letztmalig verändert: 03.02.2014, 08:55:13