(366j) Microscopic Mechanism of Polarization Switching in Ferroelectric HfO2

Ferroelectric materials are a class of insulators that can exhibit spontaneous electric polarization. HfO₂ and ZrO₂-based ferroelectrics hold significant potential for electronic device applications due to their compatibility with direct growth on Silicon substrates. However, the precise mechanisms underlying their ferroelectric behavior remain elusive. These materials do not display straightforward soft-mode transitions that lead to proper ferroelectricity, as well as multiple structural instabilities that lead to improper ferroelectricity.

Symmetry guided first-principles quantum mechanical calculations have proved highly successful in predicting microscopic mechanism of ferroelectricity. We have identified the symmetry-invariant polynomials of the order parameters that contribute to the system's energy landscape by group theory. Through first-principles calculations, we have determined the coefficients of these polynomials, providing insights into the microscopic mechanisms driving single-domain phase transition to ferroelectric phase and polarization switching. This detailed understanding is crucial for controlling and optimizing key device properties such as the energy barrier and the coercive field.

Research Interests

Ferroelectricity, Condensed matter physics, Material science, Density functional theory, Catalysis