First-Principles Study on Evolution of Magnetic Domain in Two-Dimensional BaTiO Ultrathin Film Doped with Co under Electric Field.

The magnetization mechanism of Co-doped BaTiO ultrathin films is a subject of debate, which results in difficulties with the design of new multiferroics based on BaTiO matrixes. With the aid of a first-principles approach, it was observed that when the interstitial site and Ti vacancy were filled with Co, the configuration behaved in a nonmagnetic manner, indicating the significance of the Co content. Moreover, in the case of Co substituting two neighboring Ti atoms, when a direct current field was applied in the [100] direction, the magnetic domains excluding those in the [100], [010], and [001] directions were directed away.

A first-principles study on the magnetoelectric coupling induced by Fe in a two-dimensional BaTiO(001) ultrathin film.

A first-principles approach is utilized to study the magnetoelectric coupling induced by Fe in two-dimensional BaTiO(001) ultrathin film. It is observed that the Fe impurity increases the total magnetic moment but suppresses the spontaneous polarization. Furthermore, the total magnetic moment of Fe replacing Ti is influenced by the distance between dopants and decreases with reducing distance.

A first-principles study on the influences of metal species Al, Zr, Mo and Tc on the mechanical properties of USi.

A first-principles approach is employed to study the influences of the metal species Al, Zr, Mo and Tc on the mechanical properties of U3Si2. When the Al, Zr, Mo and Tc atoms diffuse into the vacancy sites, they dissolve into the lattice, as confirmed by the solution energies. It is found that the compounds of U3Si2 with low amounts of Al, Zr, Mo, and Tc in the Si vacancies or Al, Zr, and Mo in the U vacancies can behave in the manner of ductility.

A First-Principles Study on the Multiferroic Property of Two-Dimensional BaTiO₃ (001) Ultrathin Film with Surface Ba Vacancy.

In this work, the multiferroic property of Ba-deficient BaTiO₃ (001) ultrathin film is studied employing the first-principles approach. The BaTiO₃ (001) ultrathin film is more energetically stable and behaves as a semiconductor relative to the (111) and (101) configurations, confirmed from the surface grand potential and electronic density of states. The electronic structures show that the O vacancy can switch the (001) film from a semi-conductor into a metal, while the Ba defect has a slight influence on the band gap, at a concentration of ~2.