Investigation of substitutional impact of vanadium ion (V³⁺) over conductivity and dielectric features of SrCo hexaferrites

This study investigates the impact of substituting vanadium ions (V³⁺) with varying ratios (0.00 ≤ x ≤ 0.08) in Sr_0.5Co_0.5V_xFe_12-xO₁₉ nanohexaferrites (NHFs), which are synthesized via the sol–gel method. The crystal purity and hexagonal structure of the NHFs were confirmed using X-ray diffraction (XRD) analysis. The morphology and composition were analyzed using techniques, such as TEM, HR-TEM, SEM, and EDX. The electrical features were explored using complex impedance spectroscopy, considering frequency, temperature (T), and substitution ratio. The dielectric parameters were studied over a T up to 120 °C and within 1 Hz to 3.0 MHz. An Arrhenius analysis of DC conductance determined activation energy (E_a) across Ts. The AC conductivity exhibited a frequency-dependent behavior following Jonscher's power law, influenced by V³⁺ substitution. The calculated E_a from DC conductivity indicated the involvement of polaron and electron hopping mechanisms. The SrCo-HFs exhibited semiconductor-like behavior with increasing DC conductivity at higher Ts. Dielectric constant showed frequency-dependent distribution due to V³⁺ substitution, with Maxwell–Wagner relaxation effect observed at low frequencies. Changes in dielectric parameters were explained using Koop's conduction mechanism model. Complex impedance studies revealed both resistive and capacitive responses, indicating conduction mechanism relied on grain and grain boundary contributions within hexaferrite structures influenced by ionic effects of substitution.