Structural, magnetic, electrical, and magneto-conductivity of Li_ZCd_YZn_XNi_1−(X+Y+Z)Fe₂O₄ cathode materials for energy storage device applications

Herein, Li, Cd and Zn substituted spinel nickel ferrites Li_ZCd_YZn_XNi_1−(X+Y+Z)Fe₂O₄ with different (x + y + z = 0.15, 0.3, 0.45, 0.6 and 0.75) compositions were fabricated by using sol–gel method followed by sintering treatment at 1050 °C. Single-phase cubic spinel structure of nickel ferrite compound was identified through X-ray diffraction analysis. The replacement of Cd²⁺, Zn²⁺ and Ni²⁺ cations toward tetrahedral A-site and Li⁺ and Fe³⁺ ions over octahedral B-site. From the variations in lattice parameter (8.3399–8.4380 Å), crystallite size (94.32–69.92 nm) and ionic jump length (3.611–3.653 Å), considerable enhancement in saturation magnetization (39.38–58.65 emu/g) at room temperature was obtained in the ferrimagnetic nanocomposite with increase in Li⁺, Cd²⁺, and Zn²⁺ ion concentrations. The electrical responses revealed that the better capacitance behavior of Li_ZCd_YZn_XNi_1−(X+Y+Z)Fe₂O₄ based cathode materials. Further, the electric properties of materials depend on the external magnetic field (0.1, 0.2 and 0.3 Tesla) which exhibits the variation in impedance (Z′ and Z″), dielectric (ε′ and ε″) and ac-conductivity (σ_ac) responses due to the magneto-electric coupling effect. The enhancement in all the electric and magneto-electric results represent that the prepared novel magnetic specimens could be a promising character in energy conversion and energy storage applications. Therefore, it can be utilized in the development of novel cathodes for energy storage and GMR sensor applications.