Effect of copper substitution on structural, surface morphology, and magnetic characteristics of Ni2X-hexaferrite

In this research, a series of copper-substituted X-type hexaferrite with chemical composition Sr2-x Ni2CuxFe28O46 (x = 0.0 to 1.0, Δx = 0.2) was prepared. XRD analysis confirmed the formation of the X-type phase along with W-type (both of which are hexagonal) and hematite (an orthorhombic) phases. FTIR analysis revealed three distinctive absorption bands spanning in the range of 410 cm−1 to 510 cm−1. These bands are attributed to the stretching vibrations of Fe3+- O2−, consistent with the formation of the ferrite phase. FESEM micrographs show agglomerated hexagonal plate-like structures with the small polygonal grains spread over the surfaces of these plates. The average grain size increased from 0.5 $$\mu m$$ to 3.4 $$\,\mu {m}$$ with increasing Cu content up to x = 0.8. Magnetic hysteresis loops of all prepared compositions show a soft magnetic nature (coercivity- Hc < 500 Oe). Saturation magnetization (Ms) and remanent magnetization (Mr) values decreased with increasing Cu-content from x = 0.2 to 1.0. The reduced remanence observed in the substituted compositions opens up exciting avenues for the utilization of copper-substituted Ni2X-hexaferrites in transformer cores, inductors, electromagnetic shielding, and magnetic sensors.