Magnetic properties of CoFe1.9RE0.1O4 nanoparticles (RE=La, Ce, Nd, Sm, Eu, Gd, Tb, Ho) prepared in polyol

Observation of surface effects in La-doped CoFe2O4/SiO2nanocomposites

“…The spinel structures of all samples are not completely inverse. The degree of inversion is lowered with the increasing amount of La 3+ that is consistent with the results reported by L. B. Tahar [7]. Due to the presence of La 3+ in spinel lattice the Co 2+ transfers from the octahedral sites to tetrahedral sites and Fe 3+ transfers in opposite way to relax the strain.…”

“…Most of the lattice parameters are in good agreement with those obtained by L.B.Tahar [7] (a = 8.401Å) suggesting occupation of La 3+ in the spinel lattice. However, there is no significant increase of lattice parameters of CoFe 2 O 4 upon higher La 3+ doping as would be expected [8].…”

Investigations of lanthanum doping on magnetic properties of nano cobalt ferrites

“…This can be related to the decrease in Fe 3+ -Fe 3+ (B-B) interactions resulting from doping with La 3+ ions. The La 3+ -Fe 3+ interaction as well as the La 3+ -La 3+ may exist but they are very weak [11,13]. However, the M S does not decrease linearly with La 3+ concentration.…”

“…The large size of La 3+ tries to increase the lattice parameter and the strain produced by its substitution in the cell, tries to decrease it. This has been investigated by many researchers [10,11].…”

Impact of Pr–Ni substitution on the electrical and magnetic properties of chemically derived nanosized strontium–barium hexaferrites

“…The magnetic anisotropy is the result of accumulative contributions of the magnetic cations in the crystal structure (nickel, iron and praseodymium). Mainly, Ni 2+ ions are octahedrally coordinated [30], and an increase in their number would increase the single magnetic ion anisotropy to result in the enhancement of the coercivity. Since the spin-orbital coupling is usually much stronger in the rare-earth ions, the substitution of Pr at higher dopant level (x ≥ 0.08) would also contribute for enhancing the value of coercivity.…”