Impact of RE-Gd³⁺ ion doping on structural, microstructural, magnetic, and high-temperature electrical properties of Cu_0.7Mg_0.3Fe_2−xGd_xO₄ (0.00 ≤ x ≤ 0.020) soft ferrite prepared by citrate sol-gel auto-combustion method

This study utilized the citrate sol-gel auto-combustion method to synthesize pure copper-magnesium ferrite (Cu_0.7Mg_0.3Fe₂O₄) and Gadolinium-doped Cu_0.7Mg_0.3Fe_2−xGd_xO₄ (x = 0.004, 0.008, 0.012, 0.016 and 0.020) nanoparticles. The study examined the effects on the structural, microstructure, characteristics, electrical, and magnetic properties of the resulting Mg_0.3Cu_0.7Fe₂O₄ nanoparticles of substituting trivalent rare earth gadolinium ions for trivalent iron (Fe³⁺) ions. FTIR reveals the uniformity of a single phase-cubic along with P-XRD. The prepared nanomaterials have specific surface areas ranging from 28.222 to 29.645 (m²/g), indicating the possibility of using soft ferrites in supercapacitors. The average ferrite grain size increases from 59.96 to 62.88 nm using FESEM images. The semiconducting nature of soft ferrites is confirmed by the DC resistivity range of 2.039 \(\:\times\:\) 10⁶ to 6.307 \(\:\times\:\) 10⁶ Ω-cm at curie temperature. The M-H curve’s saturation magnetization (Ms) reduces from 26.826 to 22.913 emu/g as Gd³⁺ content increases.