Solution Synthesis of Layered van der Waals (vdW) Ferromagnetic CrGeTe 3 Nanosheets from a Non-vdW Cr 2 Te 3 Template

This is the authors' abstract. We don't add key points for this paper.

CrGeTe 3 has recently emerged as a new class of two-dimensional (2D) materials due to its intrinsic long-range ferromagnetic order. However, almost all the reported synthesis methods for CrGeTe 3 nanosheets are based on the conventional mechanical exfoliation from single-crystalline CrGeTe 3, which is prepared by the complicated self-flux technique. Here we report a solution-processed synthesis of CrGeTe 3 nanosheets from a non-van der Waals (vdW) Cr 2 Te 3 template. This structure evolution from non-vdW to vdW is originated from the substitution of Ge atoms on the Cr sites surrounded by fewer Te atoms in the Cr 2 Te 3 lattice due to their smaller steric hindrance and lower energy barrier. These CrGeTe 3 nanosheets present regular hexagonal structures with a diameter larger than 1 μm and excellent stability. They exhibit soft magnetic behavior with a Curie temperature lower than 67.5 K. This non-vdW to vdW synthesis strategy promotes the development of CrGeTe 3 in ferromagnetism while providing an effective route to synthesize other 2D materials.