Chen Dong, Wang Chunlei, Peng Chengxiao
College of Physics and Electronic Engineering, Xinyang Normal University, Xinyang 464000, P. R. China.
Institute for Computational Materials Science, International Joint Research Laboratory of New Energy Materials and Devices of Henan Province, School of Physics and Electronics, Henan University, Kaifeng 475004, P. R. China.
Phys Chem Chem Phys. 2024 Mar 6;26(10):8436-8447. doi: 10.1039/d3cp04722a.
Manipulating two-dimensional (2D) magnetism in layered van der Waals (vdW) materials like FePS (FPS), with its wide-ranging applications in flexible spintronic devices, poses a persistent challenge. Through first-principles calculations, we have achieved reversible ferrimagnetic (FiM, FePS bilayer) ↔ antiferromagnetic (AFM, 1Li-intercalated FePS bilayer) ↔ ferromagnetic (FM, 2Li-intercalated FePS bilayer) phase transitions by using a Li-ion intercalation method. Intercalated Li ions significantly enhance the Fe-3d and S-3p hybridization and reduce the Fe-Fe, Li-Fe, Li-S, and Li-P bond lengths. The manipulation of 2D magnetism in Li-intercalated FPS bilayers can be attributed to the charge transfer between two FPS monolayers mediated by Li ions. Moreover, this study offers insights into the underlying physical mechanisms that govern the variations of electronic structures, 2D magnetism, magnetic anisotropy energy, and exchange couplings. Our reversible Li-ion intercalation permits straightforward de-intercalation using a two-step route, thereby reinstating the initial magnetic order of the FPS bilayer. Our purpose-designed FPS bilayer with different Li concentrations and robust exchange coupling not only enriches the Li-intercalation physics in the FPS system but also offers a general pathway for manipulating 2D magnetism in Fe-based vdW trisulfides.
在诸如FePS（FPS）等层状范德华（vdW）材料中操控二维（2D）磁性，这在柔性自旋电子器件中具有广泛应用，但一直是个挑战。通过第一性原理计算，我们利用锂离子插层方法实现了可逆的亚铁磁性（FiM，FePS双层）↔反铁磁性（AFM，1Li插层的FePS双层）↔铁磁性（FM，2Li插层的FePS双层）相变。插层的锂离子显著增强了Fe-3d和S-3p杂化，并缩短了Fe-Fe、Li-Fe、Li-S和Li-P键长。在Li插层的FPS双层中对二维磁性的操控可归因于由锂离子介导的两个FPS单分子层之间的电荷转移。此外，本研究深入了解了控制电子结构、二维磁性、磁各向异性能量和交换耦合变化的潜在物理机制。我们的可逆锂离子插层允许使用两步路线直接脱插层，从而恢复FPS双层的初始磁序。我们专门设计的具有不同Li浓度和强大交换耦合的FPS双层不仅丰富了FPS系统中的锂插层物理，还为操控铁基vdW三硫化物中的二维磁性提供了一条通用途径。
