Li Xiangyang, Li Xingxing, Yang Jinlong
Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.
Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.
J Phys Chem Lett. 2020 May 21;11(10):4193-4197. doi: 10.1021/acs.jpclett.0c01033. Epub 2020 May 11.
Exploring 2D multifunctional materials with intrinsic ferro-/ferrimagnetism and vertical ferroelectricity is a highly desirable but challenging task. Here, motivated by the recently synthesized organometallic frameworks KFe[PcFeO], we propose to realize such materials in a series of 2D KM[PcMO] (M = Cr-Co) nanosheets. First-principles calculations suggest 2D KCr[PcCrO] as a ferromagnetic half metal with a Curie temperature of 140 K, whereas others (M = Mn, Fe, and Co) are all ferrimagnetic semiconductors with the Curie temperatures between 66 and 150 K. Moreover, the structural distortion due to the out-of-plane K counterions leads to a significant vertical electric polarization. The estimated intensity of polarization for KFe[PcFeO] is 143 pC/m, with the ferroelectric phase-transition barrier being 0.38 eV per formula. This work highlights the potential of 2D organometallic frameworks such as KM[PcMO] as a versatile platform for designing multifunctional materials with simultaneous ferro-/ferrimagnetism and vertical ferroelectricity.
探索具有本征铁磁性/亚铁磁性和垂直铁电性的二维多功能材料是一项极具吸引力但又具有挑战性的任务。在此，受近期合成的有机金属框架KFe[PcFeO]的启发，我们提议在一系列二维KM[PcMO]（M = Cr - Co）纳米片中实现此类材料。第一性原理计算表明，二维KCr[PcCrO]是一种居里温度为140 K的铁磁半金属，而其他材料（M = Mn、Fe和Co）均为居里温度在66至150 K之间的亚铁磁半导体。此外，平面外K抗衡离子引起的结构畸变导致显著的垂直电极化。KFe[PcFeO]的估计极化强度为143 pC/m，每个化学式的铁电相变势垒为0.38 eV。这项工作突出了二维有机金属框架如KM[PcMO]作为设计同时具有铁磁性/亚铁磁性和垂直铁电性的多功能材料的通用平台的潜力。
