▎ 摘　　要

Nitrogen-doped reduced graphene oxide/cobalt lanthanum ferrite (NRGO/CoLaxFe2-xO4) composites were synthesized by using a facile hydrothermal process. The results of X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS) mapping indicate that the Fe3+ ions were substituted with La3+ ions in the lattice, without altering the crystal structure. X-ray photoelectron spectroscopy (XPS) result exhibits that N atoms are combined with C atoms in the reduced graphene oxide (RGO), in the form of various bonds. Hence, the composites have excellent microwave absorption performance. An optimal reflection loss of - 58.46 dB is observed at 4.88 GHz, as the composition is NRGO/CoLa0.2Fe1.8O4. Moreover, the sample NRGO/CoLa0.3Fe1.7O4 has a wide effective absorption bandwidth of 3.8 GHz, partially covering the X and Ku bands. The enhanced dipole polarization associated with the La3+ doping, the multiple interface polarization related to NRGO and CoLaxFe2-xO4, and the magnetic loss of CoLa(x)Fe(2-x)O(4)are responsible for the enhanced microwave absorption performance of the composites. It is believed that the composites have prospect of becoming high-efficiency microwave absorber.