Al3+ doping-induced proton spatial inversion symmetry breaking in two-dimensional vermiculite: Intrinsic polarization and ferroelectric switching
Abstract
To elucidate the origin of ferroelectric properties and underlying mechanisms in experimentally discovered two-dimensional (2D) vermiculite, we performed first-principles calculations on structures with varying Al3+ doping concentrations in the Mg–O octahedra. Our results reveal that intrinsic ferroelectricity stems from Al3+ induced proton symmetry breaking. Ferroelectricity emerges with doping along the x-direction, while doping along the y-direction produces antiferroelectricity. This direction dependence arises because the ferroelectric phase along y experiences stronger short-range ionic repulsion, forcing adjacent dipoles into antiparallel alignment to minimize close ionic contacts. Furthermore, the 2D vermiculite exhibits both in-plane and out-of-plane polarization, with components of 1.47, 1.37, and 0.63 e Å/proton and 0.18, 0.17, and 0.12 e Å/proton, respectively. The formation of a local dioctahedral configuration effectively reduces the ferroelectric switching barrier. Additionally, we designed 1D and 3D-P vermiculite structures to preserve semiconductor properties while mitigating the depolarization effect inherent in the antiferroelectric configuration. Compared to traditional perovskite materials, vermiculite demonstrates superior ferroelectricity and greater robustness during switching. These attributes position 2D vermiculite as a promising candidate for developing low-cost, high-performance room-temperature ferroelectric materials.
Article Details
Journal Info
Applied Physics Letters
American Institute of Physics
Authors (6)
Kunhe Yi
Engineering Research Center of Ministry of Education for Geological Carbon Storage and Low Carbon Utilization of Resources, Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, Hebei Key Laboratory of Resource Low-Carbon Utilization and New Materials, School of Materials Science and Technology, China University of Geosciences (Beijing) , Beijing 100083,
Xiaowei Li
College of Chemistry, Institute of Nuclear Science and Technology, Key Laboratory of Radiation Physics and Technology of Ministry of Education
Zixun Shi
Engineering Research Center of Ministry of Education for Geological Carbon Storage and Low Carbon Utilization of Resources, Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, Hebei Key Laboratory of Resource Low-Carbon Utilization and New Materials, School of Materials Science and Technology, China University of Geosciences (Beijing) , Beijing 100083,
Xin Liu
Yi Zhou
Guocheng Lv
Engineering Research Center of Ministry of Education for Geological Carbon Storage and Low Carbon Utilization of Resources, Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, Hebei Key Laboratory of Resource Low-carbon Utilization and New Materials, School of Materials Science and Technology, China University of Geosciences (Beijing) , Beijing 100083,