▎ 摘　　要

NOVELTY - Composite material comprises graphene and iron-cobalt alloy nanocrystal dispersion and/or coating at molar ratio of 3:7-7:3. USE - Composite material used for absorbing electromagnetic wave (claimed). ADVANTAGE - The composite material has good absorbing property and simple and easy preparation method, and utilizes easy to obtain and low cost raw materials. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of the composite material, comprising: (A) mixing graphite oxide and N-methylpyrrolidone and dispersing to obtain first dispersion liquid; (B) adding iron(III) acetylacetonate, cobalt acetylacetonate, stearylamine and potassium hydroxide to the first dispersion liquid to obtain second dispersion liquid; (C) adding hydrazine hydrate to the second dispersion liquid and introducing protective gas to obtain third dispersion liquid; (D) heating the third dispersion liquid to 160-200 degrees C, preferably 180 degrees C and reacting for 1-3 hours, preferably 2 hours; and (E) separating reaction product, washing, filtering and drying.