Enduring effect mechanism of Co(Ni) layers on excellent microwave absorption performance of carbonyl iron in seawater

• Published in: Journal of magnetism and magnetic materials Vol. 564; p. 170202
• Main Authors: Li, Yue, Li, Xueai, Jin, Kexin, Wang, Chunsheng, Guo, Wanchun, Tian, Kesong, Wang, Haiyan
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.12.2022
• Subjects: Chemical synthesis; Coating materials; Corrosion resistance; Electromagnetic properties; Ferromagnetic particles; Surfaces and interfaces; Ferromagnetic particles; Corrosion resistance; Surfaces and interfaces; Coating materials; Chemical synthesis; Electromagnetic properties
• ISSN: 0304-8853
• DOI: 10.1016/j.jmmm.2022.170202

[Display omitted] •The ferrimagnetic particles of CIP@Co(Ni) are obtained by electroless plating.•The layers of Co(Ni) both effectively increase the stability of CIP in seawater.•The protective layers of Co show little influence on magnetic loss of CIP.•The CIP@Co shows an effective absorption bandwidth of 8.56 GHz at 1.59 mm.•CIP@Co particles indicate long-life excellent microwave absorption in seawater. The microwave absorbing materials (MAMs) applied in marine environment are confronted with corrosion, therefore, in order to guarantee the long-term function, the MAMs need to possess excellent microwave absorption performance and seawater corrosion resistance simultaneously. Carbonyl iron powder (CIP) has the characteristic of broadband response caused by magnetic loss, playing an important role in practical application as an MAM. Herein, to avoid the deterioration of microwave absorption property of CIP by seawater corrosion, protective layers of electroless plating Co(Ni) are introduced with less influence on magnetic loss. The CIP coated with Co layer (CIP@Co) shows the RLmin of −57.93 dB and an effective absorption bandwidth (EAB) of 8.56 GHz, after a long-time continuous immersion in seawater, its RLmin and EAB is −71.11 dB and 8.00 GHz, respectively. The EAB of CIP@Ni after immersing in seawater is also preserved 94 %, illustrating the long-life stability of the microwave absorption performance in seawater. The little effect of Co layer on the magnetic loss of CIP and the additional anticorrosion ability of electroless plating layers are two guarantees for enduring the excellent microwave absorption performance of CIP@Co in seawater. This work provides a solution to obtain MAMs with long-life excellent microwave absorption in seawater.