Influence of rare earth ion substitutions on the structural, optical, transport, dielectric, and magnetic properties of superparamagnetic iron oxide nanoparticles

Résumé

Abstract Superparamgnetic Fe 3 O 4 and RE:Fe 3 O 4 (RE = Dy, Nd, La) nanoparticles with an average crystallite size in the range of 15–24 nm, were synthesized by co-precipitation method. The samples were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), vibrating sample magnetometer (VSM), UV–Vis spectroscopy, LCR bridge, and two-probe technique. X-ray diffraction patterns of all the investigated samples reveal the typical phase of magnetite structure, with a small contribution of orthoferrite (NdFeO 3 ) as a secondary phase in Nd:Fe 3 O 4 sample. The saturation magnetization ( M s ) of the samples has values in the range from 41.8 to 52.3 emu/g, and decreases with RE ion doping depending on the ionic radius. Negligible values of the coercivity H c and remanence M r , indicate the superparamagnetic nature of the investigated samples. The calculated values of indirect optical band gap of Fe 3 O 4 and RE:Fe 3 O 4 nanoparticles are in the range of 0.9–1.25 eV. The dielectric constant of the samples decreases, while their activation energy increases with the increasing of ionic radii of dopants.

Citer ce document

Accès au document

Ce document est hébergé sur son dépôt institutionnel d'origine.

Auteur(s)

Statistiques

Consultations : 2

Téléchargements : 0