▎ 摘　　要

NOVELTY - Preparation of graphene/yttrium-iron oxide/cobalt-iron oxide absorbing material involves adding graphite oxide to deionized water, stirring, forming a suspension, adding yttrium-iron oxide/cobalt-iron oxide composite powder to the suspension such that the mass ratio of graphite oxide and yttrium-iron oxide/cobalt-iron oxide composite powder is 1:5, stirring continuously until homogeneous mixture is formed, placing the mixture in hydrothermal reactor, reacting at 200 degrees C for 24 hours and vacuum-drying. USE - Preparation of graphene/yttrium-iron oxide/cobalt-iron oxide absorbing material (claimed). ADVANTAGE - The method efficiently provides thin and lightweight graphene/yttrium-iron oxide/cobalt-iron oxide absorbing material having high conductivity and mechanical performance, by simple method. DETAILED DESCRIPTION - Preparation of graphene/yttrium-iron oxide (Y3Fe5O12)/cobalt-iron oxide (CoFe2O4) absorbing material involves adding graphite oxide to deionized water, stirring, forming a suspension, adding yttrium-iron oxide/cobalt-iron oxide composite powder to the suspension such that the mass ratio of graphite oxide and yttrium-iron oxide/cobalt-iron oxide composite powder is 1:5, stirring continuously until homogeneous mixture is formed, placing the mixture in hydrothermal reactor, reacting at 200 degrees C for 24 hours, and vacuum-drying at 50 degrees C for 24 hours. Graphite oxide is prepared by adding natural graphite sheet, sodium nitrate and concentrated sulfuric acid into a container in ice water, adding potassium manganate, forming mixture, adding resultant mixture to a reaction bath at 35 degrees C, stirring, forming thick slurry, adding distilled water, stirring until the reaction bath temperature is increased to 90 degrees C, adding water and hydrogen peroxide, forming graphite oxide suspension, separating, washing using deionized water until neutral, and drying. The yttrium-iron oxide/cobalt-iron oxide composite powder is obtained by mixing yttrium nitrate hexahydrate and ferric nitrate nonahydrate in the molar ratio of 3:5, adding to deionized water, stirring at 80 degrees C, adding ammonia to neutral, forming sol, continuously stirring until gel is formed, drying the gel, forming yttrium-iron oxide precursor, calcining the precursor, obtaining pure phase yttrium-iron oxide powder, mixing cobalt nitrate hexahydrate and ferric nitrate nonahydrate in the molar ratio of 1:2, adding to deionized water, stirring at 80 degrees C, adding ammonia, forming sol, continuously stirring, drying the obtained gel, forming cobalt-iron oxide precursor, calcining the precursor, obtaining pure phase cobalt-iron oxide powder, and mixing yttrium-iron oxide powder and cobalt-iron oxide powder in the ratio of 3:7.