Ferroelectric, dielectric, and EMI attenuation characteristics of BaFe₂O₄/MWCNTs/epoxy nanocomposites

ABSTRACT

This study reports the synthesis of barium-ferrite (BaFe₂O₄) particles by co-precipitation method, which is employed to prepare BaFe₂O₄/multiwall carbon nanotubes (MWCNTs)/epoxy nanocomposites. Furthermore, the structural properties, ferroelectric and dielectric properties, and electromagnetic attenuation properties are studied. The role of varying concentrations of BaFe₂O₄, frequency, and temperature on dielectric behavior is studied. In the presence of applied field, dielectric constant enhances as a result of interfacial polarization with increasing BaFe₂O₄ concentration. The permittivity is highest at low frequency and decreased with increasing frequency. With temperature, initially, dielectric constant increases and then decreases as a result of charge accumulation at interfaces and leads to interfacial polarization as confirmed by ferroelectric behavior. Here, BaFe₂O₄/MWCNTs/epoxy composite (with 40 phr BFO, where phr denotes parts per hundred) exhibited the highest value of saturation polarization (P_S) ~0.31 µC/cm² and low value of remanent polarization (P_r), that is ~0.009 µC/cm². Moreover, composites exhibited high electromagnetic interference (EMI) shielding effectiveness (SE) of nearly 19 dB for 40 phr BaFe₂O₄ concentration at 11.3 GHz. Here, the reflection-dominated SE is ~1.06 dB and absorption-dominated SE is about 18.67 dB, which dominates the total SE. The absorption-dominant behavior is depicted by the BaFe₂O₄/MWCNTs/epoxy nanocomposites in EMI shielding as further conferred in the text.

GRAPHICAL ABSTRACT

KEYWORDS:

• Polymer composite
• ferrite
• interface
• dielectric
• EMI shielding

Highlights

• BaFe2O4/multiwall carbon nanotubes (MWCNTs)/epoxy nanocomposites are prepared.

• The prepared nanocomposites are ferroelectric.

• Temperature increases dielectric properties of the nanocomposites.

• Nanocomposite with 40 phr BaFe2O4 shows nearly 19 dB electromagnetic interference (EMI) shielding.

• BaFe2O4/MWCNTs/epoxy nanocomposites show more absorption-dominated EMI shielding compared to reflection.

Acknowledgements

We greatly acknowledge the Council of Scientific and Industrial Research (CSIR), India, for supporting the Research Fellowship CSIR-SRF (File no. – 09/1244(0003)/2019-EMR-1) and DST-PURSE Grant to Amity University Rajasthan, Jaipur for providing necessary facilities.

Disclosure statement

No potential conflict of interest was reported by the authors.

Author contributions

Conceptualization, methodology, material preparation, data collection, investigation, formal analysis, writing – original draft, visualization: Shivali Meena; Data collection, investigation, formal analysis, writing – visualization, review and editing: Neelam Kumari; Characterization – Vector Network Analyzer : Vishant Gahlaut; Characterization – P-E loop : Chander Shekhar; Characterization – X-ray diffractometer, scanning electron microscopy, supervision: Supratim Mitra; Validation, resources, visualization, supervision, writing – review and editing : Umesh Kumar Dwivedi.

Data availability statement

The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.

Statement of patient consent

The author’s consent to participate in this study article.

Additional information

Funding

Council of Scientific and Industrial Research (CSIR), India, Grant 09/1244(0003)/2019-EMR-1.