Flexo-elastic control factors of domain morphology in core-shell ferroelectric nanoparticles: Soft and rigid shells

Within the framework of Landau-Ginzburg-Devonshire approach we explore impact elastic anisotropy, electrostriction, flexoelectric couplings, and mismatch strain on domain structure morphology in ferroelectric core-shell nanoparticles spherical shape. We perform finite element modelling (FEM) for multiaxial nanoparticle cores covered with an elastically-isotropic soft or elastically-anisotropic rigid paraelectric shell, without strains. In case a core FEM results show that at room temperature single polarization vortex dipolar kernel can be stable if electrostriction coupling is relatively weak. With increasing anisotropic coupling, disappears replaced by complex flux-closure structures. contrast to this, performed shell shows that, temperature, properties stabilize vortex-like structures three domains. The leads noticeable curling walls. A compensates domains confined shell. Our analysis configuration reveals different types topological defects, namely Bloch point Ising lines. Furthermore, study influence radius behavior morphology, value, phase transition temperatures, derive approximate analytical expressions analyze as well diagrams.