Supercritical CO2-induced plastic deformation on two-dimensional SrZrO3 for its multiferroic performance†

Exploring advanced technology to obtain quantum materials presenting novel and unexpected electronic states upon proper manipulation is an important research endeavor. Usually, plastic deformation can lead to some amount of disruption that can result in new physical phenomena and fascinating structures. However, how to realize efficient plasticization and manipulation to obtain irreversible variation in such materials, especially those presenting quantum material behavior, is a great challenge. Herein, we show that upon plastic deformation induced by supercritical CO₂ (SC CO₂) on SrZrO₃, typically at a pressure of 16 MPa, SrZrO₃ experiences a transition from a bulk material to a two-dimensional (2D) structure. More importantly, it can be observed that the octahedral rotation of ZrO₆ is suppressed. Furthermore, plastic deformation frequently induces magnetism in SrZrO₃. Via polarization characterization, SrZrO₃ displays multiferroic characteristics, exhibiting a considerable enhancement in the saturation magnetisation strength and polarization strength. At room temperature, SrZrO₃ exhibits a saturated magnetisation of 0.1280 emu g⁻¹, accompanied by a polarization of 0.27 μC cm⁻². Therefore, this work demonstrates that plastically deformed SrTiO₃ induced by SC CO₂ can successfully transition into a quantum multiferroic material. These results establish a new method toward plastic deformation for the manipulation of the electronic properties of quantum materials.