▎ 摘　　要

Recently, intrinsic ferromagnetism of layered van der Waals compounds (such as CrCl3, CrI3, and Cr2Ge2Te6) has received widespread attention. Herein, layered van der Waals heterostructure composites of two dimensional layered magnetic material CrCl3 and graphene nanosheets (GNSs) are facilely obtained and investigated as microwave absorption materials. The complex permittivity and complex permeability of heterostructure composites can be adjusted by modulating the mass ratio of GNS and CrCl3. The real part and imaginary part of permittivity increase with the increase in the mass fraction of GNS in composites, due to the high conductivity of GNS. Thus, dielectric loss is enhanced and originates from the Debye relaxation process and the interfacial polarization process. The minimum reflection loss (RL) of the CrCl3-GNS heterostructure composite with a GNS mass fraction of 40wt. % can reach -46.2dB at a microwave frequency of 10GHz with a thickness of 1.9mm. In addition, the RL less than -10dB can be achieved at different frequencies with all thicknesses (1-5mm). This work might provide the practical application of two dimensional layered magnetic materials as ultrahigh-performance microwave absorption materials.