Boost the Crystal Installation and Magnetic Features of Cobalt Ferrite/M-Type Strontium Ferrite Nanocomposites Double Substituted by La 3+ and Sm 3+ Ions (2CoFe 2 O 4 /SrFe 12-2x Sm x La x O 19 ).
Mahmoud M HessienAli Omar TurkyAbdullah K AlanaziMohammed AlsawatMohamed H H MahmoudNader El-BagouryMohamed M RashadPublished in: Materials (Basel, Switzerland) (2021)
Spinel cobalt ferrite/hexagonal strontium hexaferrite (2CoFe 2 O 4 /SrFe 12-2x Sm x La x O 19 ; x = 0.2, 0.5, 1.0, 1.5) nanocomposites were fabricated using the tartaric acid precursor pathway, and the effects of La 3+ -Sm 3+ double substitution on the formation, structure, and magnetic properties of CoFe 2 O 4 /SrFe 12-2x Sm x La x O 19 nanocomposite at different annealing temperatures were assayed through X-ray diffraction, scanning electron microscopy, and vibrating sample magnetometry. A pure 2CoFe 2 O 4 /SrFe 12 O 19 nanocomposite was obtained from the tartrate precursor complex annealed at 1100 °C for 2 h. The substitution of Fe 3+ ion by Sm 3 - + La 3+ ions promoted the formation of pure 2CoFe 2 O 4 /SrFe 12 O 19 nanocomposite at 1100 °C. The positions and intensities of the strongest peaks of hexagonal ferrite changed after Sm 3+ -La 3+ substitution at ≤1100 °C. In addition, samples with an Sm 3+ -La 3+ ratio of ≥1.0 annealed at 1200 °C for 2 h showed diffraction peaks for lanthanum cobalt oxide (La 3 Co 3 O 8 ; dominant phase) and samarium ferrite (SmFeO 3 ). The crystallite size range at all constituent phases was in the nanocrystalline range, from 39.4 nm to 122.4 nm. The average crystallite size of SrFe 12 O 19 phase increased with the number of Sm 3+ -La 3+ substitutions, whereas that of CoFe 2 O 4 phase decreased with an x of up to 0.5. La-Sm co-doped ion substitution increased the saturation magnetization ( Ms ) value and the subrogated ratio to 0.2, and the Ms value decreased with the increasing number of double substitutions. A high saturation magnetization value ( Ms = 69.6 emu/g) was obtained using a La 3+ -Sm 3+ co-doped ratio of 0.2 at 1200 for 2 h, and a high coercive force value ( Hc = 1192.0 Oe) was acquired using the same ratio at 1000 °C.