Lattice Phase Field Model for Nanomaterials

Abstract

The lattice phase field model is developed to simulate microstructures of nanoscale materials. The grid spacing in simulation is rescaled and restricted to the lattice parameter of real materials. Two possible approaches are used to solve the phase field equations at the length scale of lattice parameter. Examples for lattice phase field modeling of complex nanostructures are presented to demonstrate the potential and capability of this model, including ferroelectric superlattice structure, ferromagnetic composites, and the grain growth process under stress. Advantages, disadvantages, and future directions with this phase field model are discussed briefly.

Vortex structure in relaxed BaTiO3/SrTiO3 superlattice

“…Racetrack memory devices, 46) which are one-dimensional magnetic nanowire devices, has caused to consider the possibility of creating analogous ferroelectric devices by placing ferroelectric structures in a one-dimensional limit. Figure 5 shows the lattice phase-field simulation 42)…”

“…Similar stable domain patterns were obtained by changing the initial random values or using a lattice phase-field model. 42) Because the interface-intermixing effect was considered in the simulation, we examined domain structures with one and no intermixing layers. The simulation results showed that interface intermixing did not significantly affect the polarization and domain structure.…”

Switching Diagram of Core-Shell FePt/Fe Nanocomposites for Bit Patterned Media

“…It was shown that micromagnetic simulations could predict the magnetic properties for FePt based exchange-coupled bit patterned media [ 22 , 23 , 24 , 25 , 26 , 27 ]; however, only a few works for core-shell shaped island composite were reported. It should be noted that the hysteresis loop of the core-shell island is very sensitive to the stacking structure of the composite.…”

“…It should be noted that the hysteresis loop of the core-shell island is very sensitive to the stacking structure of the composite. Our prior works [ 16 , 22 ] on double-layered exchange spring nanoislands demonstrated that the micromagnetic simulations could predict the magnetization hysteresis loop with domain structure evolution at a switching external field. Therefore, the main objective of this letter is to simulate various core-shell type ECC FePt/Fe structures with different core radii and shell thickness by micromagnetic simulation.…”