Highly efficient EMI shielding applications of porous nickel–iron ferrite doped with yttrium nanocomposite thin films as a multifunctional material

Herein, we report the synthesis of novel nickel ferrite doped with yttrium nanocomposite (NiFe 2− x Y x O 4 represented as NFY) thin film with multifunctional features such as mechanical robustness and strain sensing properties for EMI shielding applications in broadband microwave frequencies. The thin films of NiFe 2− x Y x O 4 were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopic methods. Inclusion of iron and yttrium nanoparticles (NPs) into nickel acts as an excellent conducting component and improves the dielectric and magnetic characteristics of the nanocomposite thin films. Due to enhanced dielectric and magnetic features, x = 0.1 nanocomposite film with thickness of 0.5 mm shows strong absorption-dominated EM shielding behaviour of shielding efficiency − 23 dB (which is equivalent to 99.77% of shielding efficiency) in the broadband microwave frequency range. Moreover, the nanocomposite films of NiFe 2− x Y x O 4 exhibit superior long-term stability of EMI shielding efficiency under applied strains. Apart from superior shielding performance, these NiFe 2− x Y x O 4 nanocomposite films exhibit outstanding strain sensing characteristics. Owing to the properties such as light weight, mechanical flexibility, improved EMI-SE and superior strain sensing properties, this ferrites-based nanocomposite film can be used in foldable and wearable modern electronic gadgets as smart covering jacket over the shield.