He Ruiman, Liu Pengyu, Wang Bing, Fan Jinbo, Liu Chang
Institute for Computational Materials Science, Joint Center for Theoretical Physics (JCTP), School of Physics and Electronics, Henan University, Kaifeng, 475004, China.
Phys Chem Chem Phys. 2023 Feb 8;25(6):5244-5250. doi: 10.1039/d2cp05823e.
Low-dimensional multiferroic systems with magnetoelectric coupling have attracted considerable attention due to their important applications in high-density low-power storage. Based on the first-principles calculations, we demonstrated that the recently proposed one-dimensional (1D) ferroelectric materials NbOCl and NbOBr have good stabilities, and found that they can be easily separated from the bulk phase. Due to the flat band near the Fermi level, the itinerant ferromagnetism can be induced over a wide range of electron-doping concentrations, and it leads to the coexistence of ferroelectricity and ferromagnetism in 1D NbOX (X = Cl, Br) and finite-length nanochains. More interestingly, there is strong magnetoelectric coupling on finite-length nanochains, which is caused by the spontaneous electrical polarization and redistribution of magnetic carriers. In addition, magnetism also can be introduced by oxygen vacancies. We also analyzed the effects of doping concentration, strain, and length on ferroelectric polarization and magnetism. Our findings provide a way to design and search low-dimensional multiferroics.
具有磁电耦合的低维多铁性体系因其在高密度低功耗存储中的重要应用而备受关注。基于第一性原理计算，我们证明了最近提出的一维（1D）铁电材料NbOCl和NbOBr具有良好的稳定性，并发现它们可以很容易地从体相中分离出来。由于费米能级附近的平带，在很宽的电子掺杂浓度范围内可以诱导出巡游铁磁性，这导致了一维NbOX（X = Cl，Br）和有限长度纳米链中铁电性和铁磁性的共存。更有趣的是，在有限长度的纳米链上存在强磁电耦合，这是由自发电极化和磁性载流子的重新分布引起的。此外，氧空位也可以引入磁性。我们还分析了掺杂浓度、应变和长度对铁电极化和磁性的影响。我们的发现为设计和寻找低维多铁性材料提供了一种方法。
