Chemical Interactions at the Interface of Au on BiSe Topological Insulator.

This study explores the intricate chemical processes at the interface between the topological insulator BiSe and deposited Au. The study mainly focused on room-temperature interactions that can cause the aging of, e.g.

Improved polarization and endurance in ferroelectric HfZrO films on SrTiO(110).

The metastable orthorhombic phase of HfZrO (HZO) can be stabilized in thin films on LaSrMnO (LSMO) buffered (001)-oriented SrTiO (STO) by intriguing epitaxy that results in (111)-HZO oriented growth and robust ferroelectric properties. Here, we show that the orthorhombic phase can also be epitaxially stabilized on LSMO/STO(110), presenting the same out-of-plane (111) orientation but a different distribution of the in-plane crystalline domains. The remanent polarization of HZO films with a thickness of less than 7 nm on LSMO/STO(110) is 33 μC cm, which corresponds to a 50% improvement over equivalent films on LSMO/STO(001).

Rotational polarization nanotopologies in BaTiO/SrTiO superlattices.

Ferroelectrics are characterized by domain structures as are other ferroics. At the nanoscale though, ferroelectrics may exhibit non-trivial or exotic polarization configurations under proper electrostatic and elastic conditions. These polar states may possess emerging properties not present in the bulk compounds and are promising for technological applications.

Control of Polar Orientation and Lattice Strain in Epitaxial BaTiO Films on Silicon.

Conventional strain engineering of epitaxial ferroelectric oxide thin films is based on the selection of substrates with a suitable lattice parameter. Here, we show that the variation of oxygen pressure during pulsed laser deposition is a flexible strain engineering method for epitaxial ferroelectric BaTiO films either on perovskite substrates or on Si(001) wafers. This unconventional growth strategy permits continuous tuning of strain up to high levels (ε > 0.