Yunlong Tang1
Institute of Metal Research, Chinese Academy of Sciences1
Yunlong Tang1
Institute of Metal Research, Chinese Academy of Sciences1
The ability to fabricate high-quality oxide films has created a vast playground to explore emergent phenomena and exotic phases which arise from the interplay of spin, charge, orbital, and lattice degrees of freedom. Several recent progresses on the finding of new types of polar topologies in ferroelectric films will be introduced, including the observation of a periodic array of flux-closure quadrants in strained ferroelectric PbTiO<sub>3</sub> films [1], the observation of room-temperature polar vortices and skyrmion lattice in PbTiO<sub>3</sub> related superlattices [2]. Moreover, we have proposed a practical way to prepare REScO<sub>3</sub> ultrathin films by a combination of precision pulsed laser deposition (PLD) and controlled post-annealing, which shows the same strain engineering effects on preparing ferroelectric polar topologies [3]. In addition, strain engineering also indicates an intermediate ferrielectric-like phase during the antiferroelectric to ferroelectric transformation within the PBZrO<sub>3</sub> films, as revealed by atomic scale scanning transmission electron microcopy [4]. These new results indicating that designing oxide films on the atomic scale may facilitate the formation of new phase components, topologies and exploration of novel physical properties of oxide films for future electronic nano-devices.<br/>[1] Y. L. Tang, Y. L. Zhu, X. L. Ma, <i>et al.</i>, Observation of a periodic array of flux-closure quadrants in strained ferroelectric PbTiO<sub>3</sub> films. Science 348, 547–551 (2015).<br/>[2] S. Das, Y. L. Tang, Z. Hong, M. A. P. Gonçalves, <i>et al.</i>, Observation of room-temperature polar skyrmions. Nature 568, 368–372 (2019).<br/>[3] S. J. Chen, Y. L. Tang, <i>et al.</i>, Strain engineering of ferroelectric topologies prepared on conventional SrTiO<sub>3</sub> substrates buffered with REScO<sub>3</sub> layers. Acta Materialia 243, 118530 (2023).<br/>[4] R. J. Jiang, <i>et al.</i>, Atomic Insight into the Successive Antiferroelectric−Ferroelectric Phase Transition in Antiferroelectric Oxides. Nano Lett. 23, 11522 (2023).