Xuan Xiaoyu, Yang Tingfan, Zhou Jian, Zhang Zhuhua, Guo Wanlin
Key Laboratory for Intelligent Nano Materials and Devices of Ministry of Education, State Key Laboratory of Mechanics and Control of Mechanical Structures, Institute for Frontier Science, Nanjing University of Aeronautics and Astronautics Nanjing 210016 China
Center for Alloy Innovation and Design, State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University Xi'an 710049 China.
Nanoscale Adv. 2022 Jan 31;4(5):1324-1329. doi: 10.1039/d1na00805f. eCollection 2022 Mar 1.
Iron arsenide (FeAs) monolayers are known as a key component for building iron-based superconductors. Here, we predict by first-principles calculations that the FeAs monolayer is a highly stable and multiferroic material with coexisting ferroelasticity and antiferromagnetism. The ferroelasticity entails a reversible elastic strain of as large as 18% and an activation barrier of 20 meV per atom, attributed to a weak hybridization between Fe d and As p orbitals. The local moments of Fe atoms are oriented out-of-plane, so that the magnetic ordering is weakly coupled to the structural polarization. Interestingly, fluorination of the FeAs monolayer can align the local moments in parallel and reorient the easy axis along the in-plane direction. As such, the fluorinated FeAs monolayer is potentially a long-sought multiferroic material that enables a strong coupling between ferroelasticity and ferromagnetism.
砷化铁（FeAs）单层被认为是构建铁基超导体的关键成分。在此，我们通过第一性原理计算预测，FeAs单层是一种高度稳定的多铁性材料，同时存在铁弹性和反铁磁性。铁弹性导致高达18%的可逆弹性应变，且每个原子的激活势垒为20毫电子伏特，这归因于Fe d轨道和As p轨道之间的弱杂化。Fe原子的局域磁矩沿面外取向，因此磁有序与结构极化的耦合较弱。有趣的是，FeAs单层的氟化可以使局域磁矩平行排列，并将易轴重新定向到面内方向。因此，氟化的FeAs单层可能是一种长期寻求的多铁性材料，它能够实现铁弹性和铁磁性之间的强耦合。
