Structure and Magnetic Properties of La3+-Substituted Strontium Hexaferrite Particles Prepared by Sol-Gel Method

Effect of La doping on structural, magnetic and microstructural properties of Ba1 − x La x Fe12O19 ceramics prepared by citrate combustion process

“…This could be considerably noted that the increase in the M S due to spin canting caused by La 3+ ions, which deviated from the collinear to a non-collinear arrangement had been occurred [28]. The enlargement in hyperfine field strength at Fe crystallographic sites might contribute to the increase in M S [26,28]. In addition, the decrease in the M S was due to a Fe 3+ (3d 5 high spin) ion forming into Fe 2+ state (3d 6 low spin) per substitution of one La 3+ ion, giving a weaken Fe 3+ -O-Fe 3+ superexchange interaction and dilution of internal magnetic field strength.…”

“…Therefore, the optimum La substitution fraction of synthesized hexaferrites ceramics was at a composition of x = 0.15. In comparison with La-doped strontium ferrites [26,28], the optimum La contents are identical. The coercive field strength (H C ) (in the order of ∼1-2.5 kOe) remarkably increases with increasing La concentration, as illustrated in Fig.…”

“…Moreover, Wang et al [24] and Grössinger et al [25] showed the substitution of Sm ions giving fine M ferrite powders and resulting increase in coercivity. Furthermore, the light rare earth ions (Re) were used in substitution for Sr (Ba) and Fe, respectively, taking into account the ionic radius of the elements and enhancing magnetic parameters [26]. Ba 2+ or Sr 2+ site replaced by a Re 3+ ion can be associated with a valence of one Fe 3+ to Fe 2+ ion per formula unit [26].…”

Microwave absorption properties of La-substituted M-type strontium ferrites

“…In all these rare earth ions, La 3+ has been studied most widely because of its comparable radius with Sr 2+ . Consequently, many synthesis techniques such as mechanical alloying [31,32], hydrothermal synthesis [33] and sol-gel [34,35] etc. have also been developed.…”

“…Recently, rare earth elements have attracted more attentions because of their good electric and magnetic properties and are widely used in the ferrite as substituted elements [23][24][25][26][27][28][29][30]. M-type strontium ferrites with Sr 2+ substituted by rare earth ions such as La 3+ [31][32][33][34][35], Pr 3+ [36,37], Nd 3+ [38,39], Sm 3+ [40], Sc 3+ [41] etc. were studied by some researchers.…”