Influence of reducing agent concentration on the structure, morphology and ferromagnetic properties of hematite (α-Fe₂O₃) nanoparticles

Hematite (α-Fe₂O₃) nanoparticles are successfully synthesized by using the chemical reduction synthesis method. The obtained XRD results revealed the formation of rhombohedral crystal structure of hematite α-Fe₂O₃with R₃c space group. Raman-forbidden LO E_u mode and E_1g mode observed at 657, 409 and 285 are clearly revealed hematite α-Fe₂O₃ formation. The prominent PL peak observed at 576 nm is attributed to stronger 3d–4sp hybridization due to the impact of size and morphology effect on synthesized hematite (α-Fe₂O₃) nanoparticles. SEM analysis revealed that the estimated average hematite nanoparticle size is reduced to be about 600–300 nm with an increase in the concentration of the reducing agent. The investigation of the magnetic properties of hematite nanoparticles showed that the product synthesized at low NaBH₄ concentration exhibited an extremely small hysteresis loop and low coercivity when compared to higher concentrations. The influence of reducing agent concentration on the structure, morphology and ferromagnetic properties of hematite (α-Fe₂O₃) nanoparticles are discussed comprehensively.