Advanced Tuning of electric and dielectric properties in Ba_0·5Ni_0.5-xCd_xFe₂O₄ spinel ferrites for high-frequency devices with barium dopants

Spinel ferrites are vital in developing next-generation technologies with potential applications covering the medical, electronic, and material industries. Nickel-cadmium spinel ferrites are soft magnetic materials having lots of applications ranging from electronics and magnetic to sensors industries. Herein, we developed cadmium-substituted spinel ferrites (Ba_0·5Ni_0.5-xCd_xFe₂O₄) and their nanocomposite with polymer polyvinyl alcohol (PVA). The results evidently indicate that the successfully developed Ba_0·5Ni_0.5-xCd_xFe₂O_4, which also confirmed the loading of PVA onto the Ba_0·5Ni_0.5-xCd_xFe₂O₄ materials. XRD results confirmed orthorhombic single-phase structure. The optimal particle size was 27.22 nm, and the minimum was 21.25 nm, respectively, as shown by Ba_0·5Ni_0·1Cd_0·4Fe₂O₄ (x = 0.4) and PVA composite of Ba_0·5Ni_0·2Cd_0·3Fe₂O₄ (x = 0.3). It was also observed that the composites showed lower particle size than nano-ferrites. Spectral analysis (Fourier Transform Infrared Spectroscopy) confirmed the formation of spinel ferrites by detecting the M − O bonds in the 400-800 cm⁻¹ region. υ₁ and υ₂ were appeared in the range 560–609 cm⁻¹ and 439-466 cm⁻¹, corresponding to M-O. The average grain size of spinel ferrites was 0.55, 0.50, 1.03, and 1.31 μm for Ba_0·5Ni_0.5-xCd_xFe₂O₄ (x = 0.1, 0.2, 0.3, and 0.4) spinel ferrites. Dielectric parameters revealed that these materials are suitable for high-frequency devices due to their low dielectric loss, high quality factor, short relaxation time, and diverse responses.