Controllable Synthesis of Submillimeter Ultrathin 2D Ferromagnetic Cr5Te8 Nanosheets by GaTe-Assisted CVD

TL;DR

This paper presents a novel GaTe-assisted CVD method for growing large-scale, ultrathin 2D ferromagnetic Cr5Te8 nanosheets with controlled size, thickness, and magnetic properties, advancing the synthesis of 2D ferromagnets.

Contribution

The study introduces a new GaTe-assisted CVD technique enabling controllable growth of large-scale, ultrathin Cr5Te8 nanosheets with enhanced magnetic properties.

Findings

Achieved Cr5Te8 nanosheets up to ~0.19 mm in size

Nanosheets with thicknesses down to ~4.8 nm

Observed intense out-of-plane ferromagnetism with TC of 172 K

Abstract

2D non-van der Waals (vdW) Cr5Te8 has attracted widespread research interest for its air stability and thickness-dependent magnetic properties. However, exploring new methods for growing larger-scale ultrathin 2D Cr5Te8 remains challenging. Here, we selected GaTe powder as precursor to supply Te monomers and fabricated large-scale 2D Cr5Te8 nanosheets. By optimizing the growth temperature and source-substrate distance (DSS), we successfully achieved Cr5Te8 nanosheets with lateral sizes of up to ~0.19 mm and corresponding thicknesses down to ~4.8 nm. The role of GaTe enhances the efficient Te atoms concentration, which promoted the lateral growth of Cr5Te8 nanosheets. Furthermore, our findings reveal the presence of Cr5Te8 nanosheets exhibiting serrated edges and a stacked structure like wedding cakes. Magnetic property measurement revealed the intense out-of-plane ferromagnetism in Cr5Te8, with the Curie temperature (TC) of 172 K. This work paves a way for the controllable growth of the submillimeter ultrathin 2D ferromagnetic crystalline and lays the foundation for the future synthesis of millimeter ultrathin ferromagnets.