College of Materials Science and Engineering, Zhengzhou University, Zhengzhou, 450001, P. R. China.
Henan Institute of Advanced Technology, Zhengzhou University, Zhengzhou, 450003, P. R. China.
Small. 2023 Jun;19(24):e2300765. doi: 10.1002/smll.202300765. Epub 2023 Mar 14.
2D magnetic materials are ideal to fabricate magneto-optical, magneto-electric, and data storage devices, which are proposed to be critical to the next generation of information technologies. Benefited from their labile structures, 2D perovskites are amenable for magnetic manipulation through structural optimization. In this work, 2D room-temperature ferromagnetic SrTiO is achieved through straining effect induced by supercritical carbon dioxide (SC CO ). According to experimental results, the cubic phase of SrTiO is converted to tetragonal with exposure of (110), (200), (111), and (211) planes over the SC CO treatment, leading to significant ferromagnetic enhancement. Theoretical calculations illustrate that over the conversion from cubic to tetragonal, the electronic structure of SrTiO is significantly modulated. Specifically, the spin density of planes of (200), (111), and (211) is enhanced, presumably due to the stabilization of the highest occupied molecular orbital over straining by SC CO , leading to magnetic optimizations. This work suggests that magnetic optimization can be achieved from SC CO -induced electronic structure modulation.
二维磁性材料是制备磁光、磁电和数据存储设备的理想材料,这些设备被认为是下一代信息技术的关键。二维钙钛矿得益于其不稳定的结构,通过结构优化可以进行磁性操控。在这项工作中,通过超临界二氧化碳(SC CO )引起的应变效应实现了二维室温铁磁体 SrTiO 。根据实验结果,在 SC CO 处理过程中,SrTiO 的立方相转变为四方相,暴露了(110)、(200)、(111)和(211)面,导致显著的铁磁增强。理论计算表明,在从立方相到四方相的转变过程中,SrTiO 的电子结构发生了显著的调制。具体来说,(200)、(111)和(211)面的自旋密度增强,可能是由于 SC CO 通过应变稳定了最高占据分子轨道,从而导致了磁性优化。这项工作表明,通过 SC CO 诱导的电子结构调制可以实现磁性优化。