基本信息
杨紫尧：2024级 硕士生
办公地点：北园物理楼206
电子邮箱：yangziyao@ruc.edu.cn
电 话：+86-10-62517997
传 真：+86-10-62517887
邮 编：100872
教育经历
(1) 2024-09 至今，中国人民大学，物理学系，硕士研究生，在读
(2) 2020-09至2024-06，东北师范大学，物理系，本科，理学学士
研究方向
代表性论文
基本信息
冯佳佳：2024级 直博生
办公地点：北园物理楼206
电子邮箱：fengjiajia@ruc.edu.cn
电 话：+86-10-62517997
传 真：+86-10-62517887
邮 编：100872
教育经历
(1) 2024-09 至今，中国人民大学，物理学系，直博，在读
(2) 2020-09 至 2024-06，山东师范大学，物理系，本科，理学学士
研究方向
层间耦合材料的第一性原理计算，氧化物材料的第一性原理计算。
代表性论文
基本信息
李文考：2024级 直博生
办公地点：北园物理楼206
电子邮箱：liwenkao@ruc.edu.cn
电 话：+86-10-62517997
传 真：+86-10-62517887
邮 编：100872
教育经历
(1) 2024-09 至今，中国人民大学，物理学系，直博，在读
(2) 2020-09 至 2024-06，山东师范大学，物理系，本科，理学学士
研究方向
低维磁性材料的第一性原理计算，预测低维材料物性。
代表性论文
Chin. Phys. B 33 086802 (2024)
Yunli Da (笪蕴力)†, Ruichun Luo (罗瑞春)†, Bao Lei (雷宝), Wei Ji (季威) and Wu Zhou (周武)*
Abstract:
The design and preparation of novel quantum materials with atomic precision are crucial for exploring new physics and for device applications. Electron irradiation has been demonstrated as an effective method for preparing novel quantum materials and quantum structures that could be challenging to obtain otherwise. It features the advantages of precise control over the patterning of such new materials and their integration with other materials with different functionalities. Here, we present a new strategy for fabricating freestanding monolayer SiC within nanopores of a graphene membrane. By regulating the energy of the incident electron beam and the in-situ heating temperature in a scanning transmission electron microscope (STEM), we can effectively control the patterning of nanopores and subsequent growth of monolayer SiC within the graphene lattice. The resultant SiC monolayers seamlessly connect with the graphene lattice, forming a planar structure distinct by a wide direct bandgap. Our in-situ STEM observations further uncover that the growth of monolayer SiC within the graphene nanopore is driven by a combination of bond rotation and atom extrusion, providing new insights into the atom-by-atom self-assembly of freestanding two-dimensional (2D) monolayers.
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Chin. Phys. B 33, 076803 (2024)
Nanshu Liu, Cong Wang, Changlin Yan, Changsong Xu, Jun Hu, Yanning Zhang, and Wei Ji
Abstract:
Hafnia-based ferroelectric materials, like Hf0.5Zr0.5O2 (HZO), have received tremendous attention owing to their potentials for building ultra-thin ferroelectric devices. The orthorhombic(O)-phase of HZO is ferroelectric but metastable in its bulk form under ambient conditions, which poses a considerable challenge to maintaining the operation performance of HZO-based ferroelectric devices. Here, we theoretically addressed this issue that provides parameter spaces for stabilizing the O-phase of HZO thin-films under various conditions. Three mechanisms were found to be capable of lowering the relative energy of the O-phase, namely, more significant surface-bulk portion of (111) surfaces, compressive caxis strain, and positive electric fields. Considering these mechanisms, we plotted two ternary phase diagrams for HZO thin-films where the strain was applied along the in-plane uniaxial and biaxial, respectively. These diagrams indicate the O-phase could be stabilized by solely shrinking the film-thickness below 12.26 nm, ascribed to its lower surface energies. All these results shed considerable light on designing more robust and higher-performance ferroelectric devices.
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