Hydrothermal Synthesis of SrFe12O19 and Its Characterization

Abstract

We have synthesized strontium hexaferrite particles in an alkaline medium using a hydrothermal process at 180°C. Crystalline phase of samples were determined by XRD and spectroscopic, morphological, and magnetic investigation of the sample were FT-IR, SEM, and TG analysis, respectively. XRD analysis revealed few impurity phases in the as-made powder; upon calcinations, the material is converted to desired hexaferrite phase. As synthesized powder exhibits agglomerates with rather smooth facets, in the form of thick platelets. Upon calcination, all these structures were observed to transfer to rod-like structures. The As calcined sample has high specific saturation magnetization (M s ) values of 65 emu/g that is close to its theoretical value of 74.3 emu/g but the hydrothermally synthesized sample does not. This is in agreement with the observations from XRD analysis where few impurity phases observed in the as-made powder cause a weak magnetic response. Upon calcination, the material is converted to a desired hexaferrite phase with better magnetic properties.

Magnetic properties of ball-milled SrFe12O19 particles consolidated by Spark-Plasma Sintering

“…The increase of M s is most likely to be associated with the increased amount of magnetite phase, as in bulk form it possesses larger saturation magnetization values2122 of about 90 emu/g, compared with strontium hexaferrite2324, which is close to 75 emu/g. The continuous increase of magnetization up to 1T and the non-saturating behavior observed in all samples could be a signature of crystallite alignment.…”

Nanoengineered High-Performance Hexaferrite Magnets by Morphology-Induced Alignment of Tailored Nanoplatelets

“…However, the influence of nanoparticle consolidation is largely neglected in the literature, as it presents numerous difficulties such as excessive crystallite growth, impurity formation, dilution of magnetic material due to binding elements, application of high external magnetic fields during compaction, or lack of magnetic orientation in the produced magnet. While many studies have been performed on the synthesis of SrFe 12 O 19 nanocrystallites obtaining promising magnetic properties, ,− few studies − cover the subsequent step in the production of permanent hexaferrite magnets, i.e., the compaction of nanoparticles into a final dense bulk magnet.…”

Influence of cobalt addition and calcination temperature on the physical properties of BaFe12O19 hexaferrites nanoparticles

“…Also, it has an excellent chemical stability and corrosion resistivity [4,5]. On the technological side, it has been used to manufacture permanent magnets, magnetic recording media, microwave devices and circuits, magneto-optic media, signal processing devices, telecommunications devices, supercapacitors and microwave filters [6][7][8][9][10][11][12][13]. Synthesis of nano-scale particles of BaFe 12 O 19 can be achieved through different methods including: co-precipitation [14,15], sol-gel [16,17], carbon combustion [18], citrate auto-combustion [19] and hydrothermal [20].…”