Tunable Ferroionic Properties in CeO/BaTiO Heterostructures.

Ferroionic materials combine ferroelectric properties and spontaneous polarization with ionic phenomena of fast charge recombination and electrodic functionalities. In this paper, we propose the concept of tunable polarization in CeO (ceria) thin (5 nm) films induced by built-in remnant polarization of a BaTiO (BTO) ferroelectric thin film interface, which is buried under the ceria layer. Upward and downward fixed polarizations at the BTO thin film (10 nm) are achieved by the lattice termination engineering of the SrO or TiO terminated Nb:SrTiO (NSTO or STN) substrate.

Uncovering the Lowest Thickness Limit for Room-Temperature Ferromagnetism of CrTe.

Metallic ferromagnetic transition metal dichalcogenides have emerged as important building blocks for scalable magnetic and memory applications. Downscaling such systems to the ultrathin limit is critical to integrate them into technology. Here, we achieved layer-by-layer control over the transition metal dichalcogenide CrTe by using pulsed laser deposition, and we uncovered the minimum critical thickness above which room-temperature magnetic order is maintained.

Route to tunable room temperature electric polarization in SrTiO-CoFeO heterostructures.

Utilizing the magnetostrictive properties of CoFeO, we demonstrate reversible room temperature control of the Ti electronic structure in SrTiO-CoFeO heterostructures, by inducing local and reversible strain in the SrTiO. By means of X-ray absorption spectroscopy, we have ascertained the changes that take place in the energy levels of the Ti 3d orbitals under the influence of an external magnetic field. The observed Ti electronic state when the sample is subjected to moderately large external magnetic fields and the disappearance of the induced phase upon their removal indicates lattice distortions that are suggestive of the development of a net electric polarization.

An integrated ultra-high vacuum apparatus for growth and in situ characterization of complex materials.

Here, we present an integrated ultra-high vacuum apparatus-named MBE-Cluster -dedicated to the growth and in situ structural, spectroscopic, and magnetic characterization of complex materials. Molecular Beam Epitaxy (MBE) growth of metal oxides, e.g.