| Title |
Electromagnetic Wave Absorption Characteristics of Patterned BaTiO3/BaZnCoFe16O27 Bilayers with Controlled Layer Thickness and Pattern Geometry |
| Authors |
허재희(Jae-Hee Heo) ; 강영민(Young-Min Kang) ; 이상민(Sang-Min Lee) |
| DOI |
https://doi.org/10.3365/KJMM.2025.63.12.955 |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Keywords |
W-type hexaferrite; BaTiO3; HFSS; EM wave absorption; Reflection loss |
| Abstract |
This study explores the electromagnetic (EM) wave absorption behavior of a bilayer structure
comprising BaZnCoFe16O27-epoxy (BZCFO) and BaTiO3-epoxy (BT). BZCFO exhibits magnetic loss via
ferromagnetic resonance (FMR) originating from BaZnCoFe16O27 particles, while BT provides high
permittivity and dielectric loss due to the ferroelectric nature of BaTiO3 particles. The composite samples were
prepared by individually mixing the synthesized single-phase powders of BaZnCoFe16O27 and BaTiO3 with 10
wt% epoxy. The complex permittivity and permeability of each layer were experimentally determined and
applied in HFSS simulations across the 0.1?18 GHz frequency range. To ensure the accuracy of the
simulation, the reflection loss (RL) results of the single-layer BZCFO structure were compared with
experimental measurements and calculations based on transmission line theory. Based on this, various
bilayer configurations were examined by adjusting the thicknesses of BZCFO (tBZCFO) and BT (tBT), and
applying different BT layer patterns: non-patterned, cross-shaped, and square island types. The nonpatterned
bilayer exhibited lower performance than the optimized single BZCFO layer, with increased tBT
causing reduced absorption due to stronger reflection. In contrast, the cross-shaped pattern exhibited
enhanced broadband absorption when tBT = 0.2 mm, tBZCFO = 2.25 mm, and the pattern width was 1.0 mm,
achieving an absorption bandwidth (Δf) of 12.51 GHz where RL remained below ?10 dB. In the case of the
square island pattern, an excellent absorption bandwidth of Δf > 12 GHz was achieved when the BT squares
had a side length of 0.75 mm and covered approximately 2?14% of the BZCFO surface. These results highlight
the potential of tailored dielectric?magnetic bilayers with patterned structures for broadband EM wave
absorption and shielding applications. |