title: Preparation and microwave absorbing properties of the core-nanoshell composite absorbers with the magnetic fly-ash hollow cenosphere as core.
abstract: Electromagnetic (EM) wave pollution has become the chief physical pollution for environment. The core-nanoshell composite absorbers with magnetic fly-ash hollow cenosphere as core and nanocrystalline magnetic material as shell were prepared by high-energy ball milling. The results of X-ray diffraction analysis (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and vector network analyzer (VNA) analysis indicated that perfect-crystalline nanomagnetic material coating was gotten with a particle size of 12 nm, being dried at 60°C for 2 hr and calcined at 400°C for 1 hr after ball milling. The exchange-coupling interaction happened between ferrite of cenosphere and soft magnet γ-Fe203 coating, it enhances magnetic loss of composite absorbers. In the frequency between 1 MHz and 1 GHz, the absorbing effectiveness of the core-nanoshell composite absorbers can achieve -30 dB, it is better than single material and is consistent with requirements of the microwave absorbing material at the low-frequency absorption.
authors.affiliation: College of Environmental and Chemical Engineering, Dalian Jiaotong University, Dalian 116028, China.
authors.forename: Ruxin
authors.initials: R
authors.lastname: Che
authors.forename: Chunxia
authors.initials: C
authors.lastname: Wang
authors.forename: Yingjuan
authors.initials: Y
authors.lastname: Ni
authors.forename: Bing
authors.initials: B
authors.lastname: Yu
mesh_terms: D065638:Absorption, Radiation; D060729:Coal Ash / Q000737:chemistry*; D004055:Differential Thermal Analysis; D008280:Magnetics; D008872:Microwaves; D057145:Nanoshells / Q000737:chemistry* / Q000648:ultrastructure; D013818:Thermogravimetry; D014961:X-Ray Diffraction
chemical_list: D060729:Coal Ash