A glass-like carbon-wrapped Y2Si₂O₇ core-shell structure for improving electromagnetic wave absorption

Electromagnetic (EM) wave absorption materials have been intensively investigated to mitigate EM wave pollution and fulfil the demands for radar cross section (RCS) reduction. Herein, Y2Si2O7@C composites with a core-shell structure that embeds Y2Si2O7 into glass-like carbon flakes are constructed to improve EM wave absorption. By controlling the phenolic resin content, the Y2Si2O7 inlaid glass-like carbon flake structures are gradually increased, resulting in controllable dielectric properties and optimization of the impedance matching characteristic, minimum reflection coefficient (RCmin), and broadest effective absorption bandwidth (EAB). The RCmin of Y2Si2O7@C composites (Y-3 sample) can reach -42 dB at a matching thickness of 3.3 mm, and the EAB covers 4.2 GHz (in the X band) at matching thicknesses varying from 2.1 mm to 3.5 mm. Moreover, at a scattering angle of 65 degrees, the RCS achieves 26 dBm(2). This work provides insight for designing novel Y2Si2O7 based EM wave absorption materials with strong RC, thin thickness, and wide EAB.