Influence of reducing agent concentration on the structure,morphology and ferromagnetic properties of hematite (a-Fe_2O_3) nanoparticles

摘要

Hematite (a-Fe_2O_3) nanoparticles are successfully synthesized by using the chemical reduction synthesis method. The obtained XRD results revealed the formation of rhombohedral crystal structure of hematite a-Fe_2O_3with R_3c space group. Raman-forbidden LO E_u mode and E_(1g) mode observed at 657, 409 and 285 are clearly revealed hematite a-Fe_2O_3 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 (a-Fe_2O_3) nanoparticles. SEM analysis revealed that the estimated average hematite nanoparti-cle 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 NaBH_4 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 (a-Fe_2O_3) nanoparticles are discussed comprehensively.