Chemické a fyzikální vlastnosti povrchů perovskitů

Student: Albons Caldentey Llorenc
Školitel: Doc. Mgr. Martin Setvín, Ph.D.
Stav práce: zadaná

Anotace:

Perovskites (chemical formula ABO3 [1]) are currently at the forefront of interest in materials research because of their wide applicability in catalysis [2], photocatalysis [3], electronics [4] or spintronics. The class of perovskites contains hundreds of stable materials thanks to the wide choice of A and B cations and further possibilities of doping at all three sites. The surface science of perovskites represents a major challenge mainly due to the ternary composition of the bulk material and consequent complex behaviour of their surfaces.

The focus of this PhD thesis are bulk-terminated surfaces of perovskites from the class of titanates and tantalates (for example KTaO3, KNbO3, SrTiO3 and BaTiO3). A successful preparation of this surface termination has been reported just recently [5,6] and the combined atomic force microcopy/scanning tunnelling microscopy has proven as an invaluable tool for characterization of these surfaces at the atomic scale. The AFM/STM will be supplemented by area-averaging analysis spectroscopic techniques, such as LEED, XPS, and LEIS. A major aspect of the research will be ferroelectricity (spontaneous electric polarization), often present in these materials, and the opportunities that ferroelectricity offers for production of renewable fuels (photocatalytic and pyrocatalytic effect). Another target of the Thesis will be the stability and evolution of the surface structure at ambient pressures and in liquids.

The candidate will be encouraged to spend at least 6 months abroad with one of our collaborators in Austria, Germany or Japan.

Left: Primitive unit cell of a perovskite. Middle: AFM image of a cleaved KTaO3 (001) surface. Right: q-Plus sensor for simultaneous AFM/STM measurements.

In case of interest, please contact Martin Setvin (martin.setvin@mff.cuni.cz), preferably before November 15, 2021

For more info about us, see https://physics.mff.cuni.cz/kfpp/vrstvy/01_News.html