Effect of Heat Treatments on the Structural and Magnetic Properties of La-Co Substituted Strontium Ferrite Films

Influence of the growth conditions on the magnetism of SrFe12O19 thin films and the behavior of Co/SrFe12O19 bilayers

“…The isomer shift (δ = 0.32 mm/s) is characteristic of Fe 3 + [33]. Since previous works have demonstrated the need for annealing the sample either in-situ or ex-situ in order to crystallize the SFO phase [34][35][36], the films were annealed at 850…”

Influence of the growth conditions on the magnetism of SrFe$_{12}$O$_{19}$ thin films and the behavior of Co / SrFe$_{12}$O$_{19}$ bilayers

“…The isomer shift (δ = 0.32 mm/s) is characteristic of Fe 3+ [32]. Since previous works have demonstrated the need for annealing the sample either in-situ or ex-situ in order to crystallize the SFO phase [33,34,35], the films were annealed at 850 • C for three hours. Figure 4 shows the spectra recorded from the films deposited at different sputtering powers for 3 hours (a) 140 W, b) 180 W, c) 220 W and d) 260 W) followed by the annealing at 850 • C. All the spectra were fitted to five sextets, each sextet corresponding to Fe 3+ in a different chemical environment (three octahedral sites -12k, 4f2, 2a-, one bipyramidal site -2b-and a tetrahedral site -4f1-) [6].…”

Thickness dependence of magnetic properties in La–Co substituted strontium hexaferrite films with perpendicular anisotropy

“…Recently, La-Co pair substituted strontium hexaferrite film (Sr-M) with perpendicular magnetization is confirmed to an effective way to enhance the intrinsic coercive force [2][3][4]. Moreover, the coercivity (H c ) increases with decreasing particle size (D) and turns to decrease as D decreases below single domain size, according to the thermal fluctuation of spins [5].…”