Magnetic properties in BaFe12O19 nanoparticles prepared under a magnetic field

Magnetic properties of nanocrystalline BaFe12O19 prepared by hydrothermal method

“…On the other hand, for both temperatures, a linear increase of the magnetization with increasing D was obtained. If we compare our results to those reported in [3,4], we found higher values (around double) of magnetization and coercive field for the samples exhibiting a grain size of 12 nm. The sample containing fine particles of 9 nm exhibits a magnetization (at 5 T) of 10 emu/g and coercive filed of 230 Oe.…”

“…The addition of BaCl 2 with the concentration here used may have caused a reduction of oxygen vacancies, increasing superexchange interactions, consequently improving M, as compared with that values reported in [3,4]. However our magnetization values are still far away from M s of bulk BaFe 12 O 19 , indicating that the disturbed surface such as: structural distortions, formation of non-magnetic layers on the surface of the nanoparticles, are important.…”

“…At room temperature, the saturation magnetization, M s , and coercive field, H c , measured in this material were 64 emu/g and 0.15 kOe, respectively [2]. Finer particles (D = 12 nm) were produced by means of the hydrothermal method (HT) by Che et al [3,4]. It was found that, at room temperature (RT), the M s value (M at H = 1 T) improved from 1.1 emu/g to 6.1 emu/g when the sample is prepared under a DC field of 0.25 T [4].…”

“…Finer particles (D = 12 nm) were produced by means of the hydrothermal method (HT) by Che et al [3,4]. It was found that, at room temperature (RT), the M s value (M at H = 1 T) improved from 1.1 emu/g to 6.1 emu/g when the sample is prepared under a DC field of 0.25 T [4]. This improvement was attributed to the increase of the superexchange.…”

The effect of post annealing treatment on the citrate sol–gel derived nanocrystalline BaFe12O19 powder: structural, morphological, optical and magnetic properties

“…For the application of the material in different fields, the material has to be synthesized in pure form, and subsequently well characterized by different techniques. For example, different preparation techniques, such as solid state reaction (Qiu et al 2005), mechanothermal , molten salt method (Topal et al 2007), co-precipitation method (Radwan et al 2007), citrate sol-gel (Mali and Ataie 2005), hydrothermal method (Wang et al 2004) and reverse micelle technique (Xu et al 2008) have been followed to design and develop the micro and nanoscale BaFe 12 O 19 materials. Among these different methods, we have selected citrate sol-gel method as it has many advantages which include relatively simple, cost effective and independence of the processing parameters, etc.…”