Fig 1

Schematic diagram of the process for fabricating laminated FeSiBCr and EM test core."

Fig 2

SEM images of powders with different milling time. (a) 3 h, (b) 4 h, (c) 5 h and (d) 6 h. (e) XRD patterns and (f) magnetic hysteretic loops of raw powder and milled powders."

Fig 3

(a) TEM image of powder with 5 h milling time. HRTEM images of (b) the surface and (c) the matrix. (d) HAADF image of 5 h milled powder with the corresponding element distribution maps."

Fig 4

(a) survey curve, (b) the fitted O 1s spectrum, (c) the high-resolution Fe 2p spectrum and (d) the detailed Si 2p of FeSiBCr flakes with 5 h milling time on an etching depth of 2 nm."

Fig 5

(a)–(d) 3D diagrams and (e)–(h) the corresponding 2D contour maps of RL values dependent thickness and frequency for powders with different milling time. The summarized (i) RLm and tR and (j) EABm and tE with milling time of 3–6 h. (k) comparison of RLm and EABm of the reported flaky soft magnetic materials [30–40]."

Fig 6

Frequency dependence of (a) ε′ and (b) ε′′ for as-milled FeSiBCr powders. ε′ versus ε′′ curves of FeSiBCr powders with different milling time: (c) 3 h, (d) 4 h, (e) 5 h and (f) 6 h."

Fig 7

Frequency dependence of (a) μ′ and (b) μ′′ for as-milled FeSiBCr powders. μ′ versus μ′′ curves of FeSiBCr powders with different milling time: (c) 3 h, (d) 4 h, (e) 5 h and (f) 6 h."

Fig 8

(a) S11, (b) S21, (c) absorption ratio, (d) α, (e) tanδE and (f) tanδM of FeSiBCr powders with different milling time."

Fig 9

The optimal RL curve and Zim curve with tR and simulated t under λ/4 model of powders with milling time of (a) 3 h, (b) 4 h, (c) 5 h and (d) 6 h."

Fig 10

EM wave loss mechanism of laminated FeSiBCr."

Fig 11

(a) Simulated RL curve based on designed periodic gradient structure (inset). The inset shows electric and magnetic loss densities of periodic gradient structure at 5.98 GHz, 7.67 GHz and 16.30 GHz. (b) Working principle of radar detectors and the RCS simulation model. 3D radar wave scattering signals of (c) PEC, (d) PEC/3 h-milled powder, (e) PEC/4 h-milled powder, (f) PEC/5 h-milled powder, (g) PEC/6 h-milled powder. (h) RCS simulation curves of PEC and PEC with different milled powder coating."