Ambient-Condition Synthesis of Cr2AlB2 Phase via Molten Salt Shielding for High-Performance Electromagnetic Wave Absorption
MAB-phase-derived compounds exhibit promising electromagnetic wave (EMW) absorption properties due to their unique layered structure and desirable physicochemical characteristics. Among them, Cr2AlB2 is particularly attractive owing to its excellent thermal and electrical conductivity. However, conventional synthesis of Cr2AlB2 requires inert gas protection to prevent oxidation, significantly increasing production costs and limiting its application in EMW absorption. To overcome this bottleneck, we report the successful synthesis of high-purity Cr2AlB2 in ambient air using the molten salt shielded synthesis (MS3) method. This approach not only isolates the material from oxygen interference but also reduces the synthesis temperature, offering a cost-effective and scalable route. The as-synthesized Cr2AlB2 exhibits outstanding EMW absorption performance: a minimum reflection loss (RLmin) of -42.10 dB at 12.6 GHz and a maximum effective absorption bandwidth (EABmax) of 3.44 GHz at a thickness of 1.9 mm. This work not only facilitates the large-scale production of Cr2AlB2 but also provides critical insights into its practical application as a high-performance EMW absorber.