Hanxiang Wu, Zuoquan Tan, Zhaxi Suonan, Shanshan Chen, Rui Xu, Wei Ji, Zhihai Cheng, and Fei Pang*
Abstract:
Although 2D self-intercalated Cr5Te8 has been successfully synthesized via chemical vapor deposition (CVD), its etching behavior remains largely unexplored. Etching, as the inverse process of material growth, is essential for understanding growth mechanisms and fabricating nanosheet patterns. Herein, we explore the anisotropic etching of 2D Cr5Te8 assisted by an excess Te supply. The etching process initiates from both the surface and the edge, creating distinct holes and nanoribbons with triangular or hexagonal shapes. To the best of our knowledge, this is the first report on controllable anisotropic etching patterns in 2D Cr5Te8. Furthermore, magnetic measurements reveal ferromagnetism in the etched nanosheets with a Curie temperature (TC) of 164 K, slightly lower than that of the unetched nanosheets. The etched nanosheets exhibit an enhanced saturated magnetic field of 38.5 kOe, approximately 3.2 times that of the unetched nanosheets. This enhancement in the saturated magnetic field is attributed to the pattern-induced strengthening of the reentrant stray field. This study offers a new direction for preparing patterned 2D materials and opens a novel avenue for modulating 2D magnetism.
Two-dimensional (2D) non-van der Waals (vdW) Cr5Te8 has attracted widespread research interest for its air stability and thickness-dependent magnetic properties. However, the growth of large-scale ultrathin 2D Cr5Te8 remains challenging. Here, we selected GaTe powder as the precursor to supply Te monomers and fabricated submillimeter 2D Cr5Te8 nanosheets. By optimizing the growth temperature and source–substrate distance (DSS), we successfully achieved Cr5Te8 nanosheets with a lateral size of up to ∼0.19 mm and corresponding thickness down to ∼4.8 nm. The role of GaTe is to enhance the efficient Te atom concentration, which promotes the lateral growth of Cr5Te8 nanosheets. Furthermore, our findings reveal the appearance of Cr5Te8 nanosheets exhibiting serrated edges and a stacked structure like those of wedding cakes. Magnetic property measurement revealed the intense out-of-plane ferromagnetism in Cr5Te8, with a Curie temperature (TC) of 172 K. This work paves the way for the controllable growth of submillimeter ultrathin 2D ferromagnetic crystals and lays the foundation for the future synthesis of millimeter ultrathin ferromagnets.
Hanxiang Wu, Jianfeng Guo, Suonan Zhaxi, Hua Xu, Shuo Mi, Le Wang, Shanshan Chen, Rui Xu, Wei Ji, Fei Pang and Zhihai Cheng
Abstract:
As a unique 2D magnetic material with self-intercalated structure, Cr5Te8 exhibits many intriguing magnetic properties. While its ferromagnetism of Cr5Te8 has been previously reported, the research on its magnetic domain remains unexplored. Herein, we have successfully fabricated 2D Cr5Te8 nanosheets with controlled thickness and lateral size by chemical vapor deposition (CVD). Then magnetic property measurement system revealed Cr5Te8 nanosheets exhibiting intense out-of-plane ferromagnetism with a Curie temperature (TC) of 176 K. Significantly, we reported for the first time two magnetic domains: magnetic bubbles and thickness-dependent maze-like magnetic domains in our Cr5Te8 nanosheets by cryogenic magnetic force microscopy (MFM). The domain width of the maze-like magnetic domains increases rapidly with decreasing sample thickness, meanwhile domain contrast decreases. This indicates the dominate role of ferromagnetism shifts from dipolar interactions to magnetic anisotropy. Our research not only establishes a pathway for the controllable growth of 2D magnetic materials, but also points towards novel avenues for regulating magnetic phases and methodically tuning domain characteristics.
