Heng Zhang

Extensive studies have shown that (110)-oriented ferroelectric films exhibit unique structures and excellent physical properties compared with (001)-oriented ferroelectric films. Showing how the domain structure evolve as the function of epitaxial strain, or establishing a strain phase diagram, should provide valuable information for the controllin...

A dipole wave is composed of head-to-tail connected electric dipoles in the form of sine function. Potential applications in information carrying, transporting, and processing are expected, and logic circuits based on nonlinear wave interaction are promising for dipole waves. Although similar spin waves are well known in ferromagnetic materials for...

High-index-oriented epitaxial ferroelectric films have recently attracted great attention due to their emergent functional properties related to the multi-domain structures. Here, the equilibrium phases and domain structures in (111)-oriented ferroelectric PbTiO3 films were investigated via phase-field simulations and the misfit strain-temperature...

Phase coexistence in ferroelectric oxide films displays complex phase competitions and transformation which suggest new multiple-coupled properties. Here we have successfully engineered the coexistence of flux-closure and a1/a2 phases in tensile-strained PbTiO3 films sandwiched between GdScO3 substrate and a SrTiO3 layer. Moreover, by using in-situ...

Ferroelectric thin films with high index orientations are found to possess unique structures and properties. In this work, we constructed the misfit strain-misfit strain phase diagram of (110)-oriented PbTiO3 (PTO) thin films by phase-field simulations. The evolutions of ferroelectric phase structures, domain morphologies, volume fractions, and pol...

The interaction of domain structure and defects in ferroelectric thin films has been studied for decades. However, the role of dislocations and thermal stability of microstructures are still poorly studied. By combining transmission electron microscopy, X-ray diffraction experiments and phase-field simulations, we show that dislocation pairs induce...

By combining phase-field simulations and first-principles calculations, we proposed to modulate the monoclinic phases of high-index-oriented PbTiO3 films through epitaxial anisotropic strain to obtain superior piezoelectric performance. It was found that the piezoelectric coefficients e22 were remarkably enhanced (up to 2400%) in both (111)- and (1...

Engineering regular surface crystallographic facet arrays on a large scale is useful for tuning and optimizing photophysical properties of optoelectronic materials. Herein, we achieve textured Bi0.5La0.5FeO3 (BLFO) film surfaces displaying nanosquare arrays composed of {001} and {110} crystallographic facets, via an effective and controllable therm...