Magnetic properties of nanocrystalline CoFe2O4 synthesized by modified citrate-gel method

The effect of annealing on the structure, magnetic properties and AC heating of CoFe2O4 for biomedical applications

“…saturation magnetization (Ms) becomes 27.6 emu/g, which is very much higher than that of both oxides. It is important to note that this value is still smaller than that of pure CoFe 2 O 4 as reported in the literature [8][9][10][11][12][13][14][15]. Therefore, milling resulted in a partial formation of CoFe 2 O 4 .…”

“…Several techniques have been employed to synthesize this material at the nanoscale. These methods include sol-gel [3,6], micelle chemical control method (micro-emulsion) [7], citrate-gel method [8,9], hydrothermal process [10], polymerized complex method [11], mechanical alloying [8,12,13], mechanochmical method [14], and electrospinning [15].…”

Effect of high magnetic field annealing on the microstructure and magnetic properties of Co–Fe layered double hydroxide

“…From the XRD and magnetization results, CoFe 2 O 4 was formed at about 500 1C under the magnetic field annealing, whereas it was formed at about 600 1C without magnetic field. It is well known that CoFe 2 O 4 is ferromagnetic at 500 1C because the Curie temperature for CoFe 2 O 4 is about 520 1C [20]. When a magnetic field is applied at about 500 1C, the total free energy of the ferromagnetic phase is reduced by magnetic energy.…”

Elaboration of superparamagnetic cobalt–ferrite nanocomposites from films of chitosan chelates

“…36,38 Moreover, both samples showed a significantly reduced magnetization saturation value with respect to the bulk cobalt-ferrite (94 A m 2 /kg). 34,38,39 It has been reported that this reduction can be associated with magnetic frustration over the interactions between a magnetic disordered phase on a surface layer of the particles (e.g., spin-glass ordering) and its magnetically ordered core. 39,40 These intraparticle interactions are clearly shown in Figure 5, where the aforementioned M(H) hysteresis loops at 1.8 K are compared with those obtained after a field-cooled (FC) process at 7 T. There is a noticeable shift in the hysteresis loops of both samples, which indicates a preferred orientation of the magnetic moment of the particles.…”