Pinning of a ferroelectric Bloch wall at a paraelectric layer

The phase-field simulations of ferroelectric Bloch domain walls in BaTiO3–SrTiO3 crystalline superlattices performed in this study suggest that a paraelectric layer with a thickness comparable to the thickness of the domain wall itself can act as an efficient pinning layer. At the same time, such a layer facilitates the possibility to switch domain wall helicity by an external electric field or even to completely change the characteristic structure of a ferroelectric Bloch wall passing through it. Thus, ferroelectric Bloch domain walls are shown to be ideal nanoscale objects with switchable properties. The reported results hint towards the possibility to exploit ferroelectric domain wall interaction with simple nanoscale devices.

Micromagnetic Simulation on Ground State Domain Structures of Barium Hexaferrite (BaFe12O19)

We have systematically investigated the domain structures of Barium Hexaferrite (BaFe12O19) by means of a micromagnetic simulation under zero external magnetic field. A hexagonal-shaped and cylindrical-shaped models are used in this simulation with respect to the diameter variation from 50 nm to 600 nm. A transition domain structure is found from a single-domain (SD) to multi-domain (MD) at a certain diameter. The hexagonal-shaped occurs in diameter 430 nm and cylindrical-shaped in diameter 410 nm. Interestingly, the domain wall of MD structure exhibits a Bloch-wall type. The domain wall width is determined by full width half maximum (FWHM) method from the transverse magnetization component data. The domain wall width from simulation showed close to Kittel’s formula