Highly anisotropic Fe<sub>3</sub>C microflakes constructed by solid-state phase transformation for efficient microwave absorption.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 38374257.
- Also identified by DOI 10.1038/s41467-024-45815-w and PMC identifier 10876570.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Soft magnetic materials with flake geometry can provide shape anisotropy for breaking the Snoek limit, which is promising for achieving high-frequency ferromagnetic resonances and microwave absorption properties. Here, two-dimensional (2D) Fe<sub>3</sub>C microflakes with crystal orientation are obtained by solid-state phase transformation assisted by electrochemical dealloying. The shape anisotropy can be further regulated by manipulating the thickness of 2D Fe<sub>3</sub>C microflakes under different isothermally quenching temperatures. Thus, the resonant frequency is adjusted effectively from 9.47 and 11.56 GHz under isothermal quenching from 700 °C to 550 °C. The imaginary part of the complex permeability can reach 0.9 at 11.56 GHz, and the minimum reflection loss (RL<sub>min</sub>) is -52.09 dB (15.85 GHz, 2.90 mm) with an effective absorption bandwidth (EAB<sub>≤-10 dB</sub>) of 2.55 GHz. This study provides insight into the preparation of high-frequency magnetic loss materials for obtaining high-performance microwave absorbers and achieves the preparation of functional materials from traditional structural materials.