Yin Hang, Zhu Huapei, Wang Shuanhu, Jin Kexin
Shaanxi Key Laboratory of Condensed Matter Structures and Properties and MOE Key Laboratory of Materials Physics and Chemistry Under Extraordinary Conditions, School of Physical Science and Technology, Northwestern Polytechnical University, Xi'an 710072, China.
ACS Appl Mater Interfaces. 2024 May 22;16(20):26915-26921. doi: 10.1021/acsami.4c03115. Epub 2024 May 8.
Multifunctional integration in a single device has always been a hot research topic, especially for contradictory phenomena, one of which is the coexistence of ferroelectricity and metallicity. The complex oxide heterostructures, as symmetric breaking systems, provide a great possibility to incorporate different properties. Moreover, finding a series of oxide heterostructures to achieve this goal remains as a challenge. Here, taking the advantage of different physical phenomena, we use H plasma to pretreat the SrTiO (STO) substrate and then fabricate HfO/STO heterostructures with it. The novel, well-repeatable metallic two-dimensional electron gas (2DEG) is directly obtained at the heterointerfaces without any further complex procedures, while the obvious ferroelectric-like behavior and Rashba spin-orbit coupling are also observed. The understanding of the mechanism, as well as the modified facile preparation procedure, would be meaningful for further development of ferroelectric metal in complex oxide heterostructures.
在单个器件中实现多功能集成一直是一个热门的研究课题，特别是对于一些相互矛盾的现象而言，其中之一就是铁电性与金属性的共存。复杂氧化物异质结构作为对称破缺系统，为整合不同特性提供了极大的可能性。此外，找到一系列氧化物异质结构来实现这一目标仍然是一项挑战。在此，利用不同的物理现象，我们用氢等离子体预处理SrTiO（STO）衬底，然后用它制备HfO/STO异质结构。无需任何进一步的复杂程序，就在异质界面处直接获得了新颖的、可重复的金属二维电子气（2DEG），同时还观察到了明显的类铁电行为和Rashba自旋轨道耦合。对其机理的理解以及改进后的简便制备工艺，对于复杂氧化物异质结构中铁电金属的进一步发展将具有重要意义。
