Meng Lingjia, Zhou Zhang, Xu Mingquan, Yang Shiqi, Si Kunpeng, Liu Lixuan, Wang Xingguo, Jiang Huaning, Li Bixuan, Qin Peixin, Zhang Peng, Wang Jinliang, Liu Zhiqi, Tang Peizhe, Ye Yu, Zhou Wu, Bao Lihong, Gao Hong-Jun, Gong Yongji
School of Materials Science and Engineering, Beihang University, 100191, Beijing, P. R. China.
School of Physics, Beihang University, 100191, Beijing, P. R. China.
Nat Commun. 2021 Feb 5;12(1):809. doi: 10.1038/s41467-021-21072-z.
The discovery of ferromagnetic two-dimensional van der Waals materials has opened up opportunities to explore intriguing physics and to develop innovative spintronic devices. However, controllable synthesis of these 2D ferromagnets and enhancing their stability under ambient conditions remain challenging. Here, we report chemical vapor deposition growth of air-stable 2D metallic 1T-CrTe ultrathin crystals with controlled thickness. Their long-range ferromagnetic ordering is confirmed by a robust anomalous Hall effect, which has seldom been observed in other layered 2D materials grown by chemical vapor deposition. With reducing the thickness of 1T-CrTe from tens of nanometers to several nanometers, the easy axis changes from in-plane to out-of-plane. Monotonic increase of Curie temperature with the thickness decreasing from ~130.0 to ~7.6 nm is observed. Theoretical calculations indicate that the weakening of the Coulomb screening in the two-dimensional limit plays a crucial role in the change of magnetic properties.
铁磁二维范德华材料的发现为探索有趣的物理现象和开发创新的自旋电子器件提供了机会。然而，这些二维铁磁体的可控合成以及在环境条件下提高其稳定性仍然具有挑战性。在此，我们报告了具有可控厚度的空气稳定二维金属1T-CrTe超薄晶体的化学气相沉积生长。其长程铁磁有序通过稳健的反常霍尔效应得到证实，这在通过化学气相沉积生长的其他层状二维材料中很少被观察到。随着1T-CrTe的厚度从几十纳米减小到几纳米，易轴从面内变为面外。观察到居里温度随着厚度从130.0纳米减小到7.6纳米而单调增加。理论计算表明，二维极限下库仑屏蔽的减弱在磁性能变化中起关键作用。
