Hierarchical engineering of CoNi@Air@C/SiO2 @Polypyrrole multicomponent nanocubes to improve the dielectric loss capability and magnetic-dielectric synergy

Impedance matching characteristics and loss capabilities including magnetic loss, polarization loss and conduction loss are critical factors to improve microwave absorption performances (MAPs). To elevate these aspects, herein, yolk-shell structured CoNi@Air@C/SiO2@Polypyrrole (PPy) magnetic multicompo-nent nanocubes (MCNCs) were designed and successfully fabricated in high efficiency through a contin-uous co-precipitation route, classical Stober method, thermal treatment and polymerization reaction. The obtained results indicated that the formation of SiO2 effectively stabilized the cubic geometrical mor-phology and yolk-shell structure during the high-temperature pyrolysis process. The introduction of PPy greatly boosted their polarization loss and conductive loss capabilities. Therefore, the as-prepared yolk-shell structured CoNi@Air@C/SiO2 @PPy MCNCs presented superior MAPs compared to CoNi@Air@C/SiO2 MCNCs. Furthermore, by regulating the content of PPy, the obtained CoNi@Air@C/SiO2 @PPy MCNCs dis-played tunable and excellent comprehensive MAPs in terms of strong absorption capabilities, broad fre-quency bandwidths and thin matching thicknesses, which could be ascribed to the unique structure and excellent magnetic-dielectric synergistic effect. Therefore, our findings provided an alternative pathway to effectively utilize the magnetic-dielectric synergy and loss capabilities for the developing yolk-shell structured magnetic MCNCs as the strong wideband microwave absorbers.(c) 2023 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

Automated summary

The authors designed and fabricated yolk-shell structured magnetic multicomponent nanocubes with optimized absorption performance. This study provides a new and effective approach for the development of strong wideband microwave absorbers.