德国亥姆霍兹德累斯顿-罗森多夫研究中心(Helmholtz-Zentrum Dresden-Rossendorf, HZDR)与德累斯顿工业大学(TUD)领导的一个德美研究团队，在《Nano Letters》期刊上提出了一项创新理念，旨在改善超薄材料的性能。该理念通过让二维(2D)材料与氢反应，克服了当前无法良好控制这类材料磁性状态的局限。
2D材料因其仅由一层或多层原子构成的超薄特性，以及在自旋电子学和存储领域的潜在应用，成为近年来材料科学中的一个新兴研究热点。特别是2017年以来，科研人员发现了具有磁性的2D材料，然而这些材料在通过化学手段有目标地在两种磁性状态之间切换方面存在困难，这是构建新型电子元件的前提条件。针对这一问题，HZDR与TUD的研究小组，由青年研究小组负责人Rico Friedrich带领，聚焦于一类特殊的2D材料——非范德华2D材料，这些材料源自化学键较强的晶体。
通过详尽计算和密度泛函理论，研究团队从先前开发的包含35种新型2D材料的数据库中筛选出4种有潜力的材料。最终确定的三种候选材料，包括镉钛氧化物(CdTiO3)，在氢化处理后显示出可被特定调控的磁性。镉钛氧化物在氢的影响下转变为铁磁体，即永久磁铁，表明通过氢化钝化，可以有效调整这些超薄材料的磁性，使其适合新型电子组件的开发。由于这些材料极薄，易于整合进平面器件中，对于实际应用具有重要意义。
目前，多个研究团队正致力于实验验证这些理论发现，包括卡塞尔大学和位于德累斯顿的莱布尼茨固态与材料研究所。HZDR和TUD的研究者们也在继续探索2D材料的新类型，特别是那些可能在未来用于能源转换和存储的材料，如水分解制备绿色氢气，作为太阳能和风能不足时的储能介质。
这项研究不仅揭示了通过氢化钝化来调节非范德华2D材料磁性状态的可能性，还强调了大数据挖掘和自主理论计算在材料科学领域的强大作用，为设计和优化新材料提供了新的途径。
Article: Magnetic State Control of Non-van der Waals 2D Materials by Hydrogenation
Nano Letters has published an article written by Tom Barnowsky, Theoretical Chemistry, Technische Universität Dresden, Dresden 01062, Germany, and Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Dresden 01328, Germany, Stefano Curtarolo, Center for Extreme Materials, Duke University, Durham, North Carolina 27708, United States, and Materials Science, Electrical Engineering, and Physics, Duke University, Durham, North Carolina 27708, United States, Arkady V. Krasheninnikov, Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Dresden 01328, Germany, Thomas Heine, Theoretical Chemistry, Technische Universität Dresden, Dresden 01062, Germany, and Center for Advanced Systems Understanding (CASUS), Helmholtz-Zentrum Dresden-Rossendorf, Görlitz 02826, Germany, and Rico Friedrich, Theoretical Chemistry, Technische Universität Dresden, Dresden 01062, Germany, Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Dresden 01328, Germany, and Center for Extreme Materials, Duke University, Durham, North Carolina 27708, United States.
Abstract: “Controlling the magnetic state of two-dimensional (2D) materials is crucial for spintronics. By employing data-mining and autonomous density functional theory calculations, we demonstrate the switching of magnetic properties of 2D non-van der Waals materials upon hydrogen passivation. The magnetic configurations are tuned to states with flipped and enhanced moments. For 2D CdTiO3 ─ a diamagnetic compound in the pristine case ─ we observe an onset of ferromagnetism upon hydrogenation. Further investigation of the magnetization density of the pristine and passivated systems provides a detailed analysis of modified local spin symmetries and the emergence of ferromagnetism. Our results indicate that selective surface passivation is a powerful tool for tailoring magnetic properties of nanomaterials, such as non-vdW 2D compounds.“
