Electric–magnetic synergism in BaTiO3-magnetic microwire/silicone rubber composites for enhanced microwave and electromagnetic shielding tunability

• Published in: European physical journal plus 2023-09, Vol.138 (9), p.821, Article 821
• Main Authors: Estevez, D., Uddin, A., Salem, M.
• Format: Article
• Language: English
• Subjects: Anisotropy; Applied and Technical Physics; Atomic; Barium; Barium titanates; Complex Systems; Composite materials; Condensed Matter Physics; Dipoles; Elastomers; Electric fields; Electromagnetic properties; Electromagnetic shielding; Electronics; Ferroelectric materials; Ferroelectricity; Ferromagnetic materials; Ferromagnetic resonance; Fillers; Flexibility; Flexible components; Graphene; Heterostructures; Hysteresis; Magnetic anisotropy; Mathematical and Computational Physics; Microwave attenuation; Molecular; Nanoparticles; Optical and Plasma Physics; Permeability; Permittivity; Physics; Physics and Astronomy; Piezoelectricity; Polymers; Radiation; Regular Article; Rubber; Scanning electron microscopy; Silicone rubber; Silicones; Surface tension; Synergism; Synergistic effect; Theoretical; Wire
• ISSN: 2190-5444; 2190-5444
• DOI: 10.1140/epjp/s13360-023-04451-x

Barium titanate (BT) is a well-known electroceramic attractive for microwave applications owing to its exceptional ferroelectric characteristics, elevated dielectric constant, and piezoelectricity. BT is usually blended with conductive/magnetic fillers (mostly 0D and 3D micro/nanostructures) to better tailor its electromagnetic properties based on synergistic effects. However, complex synthesis, filler agglomeration, and high ceramic filler concentration inevitably lead to flexibility degradation, limiting its application in modern electronics. Here, we exploit magnetoelectric coupling effects in which ferroelectricity and ferromagnetism coexist to modulate the shielding properties of BT/silicone rubber composites via incorporating ferromagnetic microwires. The high dielectric constant of BT and electric hysteresis effects contributed to microwave attenuation. At the same time, its piezoelectricity modified the wire’s magnetic anisotropy via interfacial strain. In turn, the microwires promoted magnetic losses mainly by ferromagnetic resonance and magnetic hysteresis while also affecting dipole rotation in BT via wire–wire-dipolar magnetic interaction. The efficient synergism between the fillers resulted in enhanced transmission and shielding tunability, reaching a maximum shielding of 16 dB at 9.5 GHz for composites incorporating 30 wt.% BT and six microwires (0.0126 vol%) compared to 2.26 dB for composites with merely BT. Moreover, benefiting from the elastomer matrix and low filler content, these composites have potential in flexible electronics. At the same time, it also constitutes a platform for designing shielding materials based on ferroelectric/ferromagnetic heterostructures.