2025/07/22 by Yonghao Zhu, Zhi Wang, Zhu, Yonghao +4
Engineering · Materials Science · #Electronic and Structural Properties of Oxides #FOS: Physical sciences #Ga2O3 and related materials #Materials Science (cond-mat.mtrl-sci) #Semiconductor materials and devices
paper · pdf · doi:10.48550/arxiv.2507.16167
openalex publication_date 2025/07/22 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The large discrepancy between experimental and theoretical remanent polarization and coercive field limits the applications of wide-band-gap ferroelectric materials. Here, using a machine-learning potential trained on ab-initio molecular dynamics data, we identify a new mechanism of the interplay between polarization domain wall (PDW) and lattice domain wall (LDW) in ferroelectric k-phase gallium oxide (Ga2O3), which reconciles predictions with experimental observations. Our results reveal that the reversal of out-of-plane polarization is achieved through in-plane sliding and shear of the Ga-O sublayers. This pathway creates strong anisotropy in PDW propagation, and crucially leads to topologically forbidden PDW propagation across the 120 degree LDWs observed in synthesized samples. The resulting stable network of residual domain walls bypasses slow nucleation and suppresses the observable polarization and coercive field. These insights highlight the potential for tailoring the ferroelectric response in k-Ga2O3 from lattice-domain engineering.