Structural, optical and magnetic properties of Y-doped CoFe2O4 nanoparticles prepared by a simple co-precipitation method

In this work, the effect of the annealing temperature and the content of doped yttrium ions on the structural, optical, and magnetic properties of the spinel nanoparticles CoFe2-xYxO4 (0 <= x <= 0.2) synthesized by the simple co-precipitation method without any organic gelation agent have been studied. The particle size measured from powder X-ray diffraction (PXRD) patterns, and transmission electron microscope (TEM) images confirm the nanostructural character in the range of 22-40 nm. The structural characteristics (crystal size (D-XRD, nm), crystalline intensity (I, cts), and CoFe2O4 crystalline phase content), magnetic properties (remanent magnetization (M-r, emu g(-1)), and saturation magnetization (M-s, emu g(-1))), as well as band gap energy values (E-g, eV), increased with increasing annealing temperature, while changes in coercivity values (H-c, Oe) followed the opposite trend. When the yttrium ion content in the CoFe2O4 spinel crystal lattice increased, all the values of D-XRD, H-c, M-r, M-s, and E-g decreased. CoFe2-xYxO4 nanoparticles (x = 0, 0.05, 0.1, 0.15, and 0.2) have comparable H-c and lower E-g, but a much larger M-r, and especially M-s, than cobalt ferrite doped with different elements such as Y3+, Sm3+, Ce4+, or La3+. The excellent optical and magnetic properties of Y-doped CoFe2O4 nanoparticles suggest great potential for applications related to optics and magnetism.