Microwave absorption properties of Fe@Al 2O 3 nanoembedments prepared by mechanosynthesis

• Published in: Materials chemistry and physics Vol. 130; no. 1; pp. 615 - 618
• Main Authors: Zhang, Zi-dong, Shi, Zhi-cheng, Fan, Run-hua, Gao, Meng, Guo, Jing-yan, Qi, Xiao-gang, Sun, Kang-ning
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 2011
• Subjects: A. Composite materials; B. Powder metallurgy; C. Magnetometer; D. Magnetic properties; D. Magnetic properties; A. Composite materials; C. Magnetometer; B. Powder metallurgy
• ISSN: 0254-0584; 1879-3312
• DOI: 10.1016/j.matchemphys.2011.07.033

► We prepared Fe@Al 2O 3 nanocomposites by mechanochemical process. ► The nano−sized metal particle embedded uniformly in the Al 2O 3 matrix. ► The microwave properties were measured by Vector Network Analyzer. ► The maximum reflection loss can reach −21.4 dB at a higher frequency of ∼13.3 GHz. The iron nanoparticles embedded in alumina powder (Fe@Al 2O 3 nanoembedments) were prepared by a mechanochemical process. Their potential for microwave absorber is evaluated. The insulating embedment provides encapsulation and prevents oxidation and agglomeration of metal nanoparticles. The hysteresis loop of such nanoembedments at room temperature exhibits a superparamagnetic behavior, while the microwave permeability spectra show a multiresonance behavior. The maximum reflection loss can reach −21.4 dB at a higher frequency of ∼13.3 GHz as the thickness is 1.4 mm. The coexistence of superparamagnetic loss and multiresonant loss is responsible for microwave absorption. The Fe@Al 2O 3 nanoembedments may become attractive candidates for a new type of microwave absorber.