Controllable Synthesis of Submillimeter Ultrathin Two-Dimensional Ferromagnetic Cr5Te8 Nanosheets by GaTe-Assisted Chemical Vapor Deposition

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 (D_SS), 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 (T_C) 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.