Barium hexaferrite nanoparticles with high magnetic properties by salt-assisted ultrasonic spray pyrolysis

• Published in: Journal of alloys and compounds Vol. 583; pp. 145 - 150
• Main Authors: An, Guk-Hwan, Hwang, Tae-Yeon, Kim, Jongryoul, Kim, JinBae, Kang, Namseok, Kim, Seil, Choi, Yo-Min, Choa, Yong-Ho
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 2014; Elsevier
• Subjects: Barium hexaferrite; Chemical synthesis methods; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Crystallinity; Exact sciences and technology; High coercivity; Magnetic properties; Magnetic properties and materials; Magnetic properties of nanostructures; Materials science; Methods of nanofabrication; Molten salt; Nanoparticles; Non-agglomerate; Nucleation; Physics; Saturation (magnetic); Spray pyrolysis; Ultrasonic spray pyrolysis; Ultrasonic testing; High coercivity; Barium hexaferrite; Non-agglomerate; Ultrasonic spray pyrolysis; Molten salt; Scanning electron microscopy; Hexagonal ferrites; Magnetization; Crystallinity; XRD; Nanoparticles; Transmission electron microscopy; Temperature effects; Coercive force; Barium ferrites; Microstructure; Nanomaterial synthesis; Saturation magnetization
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2013.08.105

•The first time to synthesize the hexagonal ferrites by ultrasonic spray pyrolysis.•Extremely short reaction time (20s) and relatively low reaction temp. (950°C).•Preventing agglomeration, and accelerating the nucleation and growth by NaCl.•High magnetic properties of the particles, compared to those of conventional ones. Herein, we synthesized non-agglomerated barium hexaferrite nanoparticles by salt-assisted ultrasonic spray pyrolysis at different reaction temperatures. NaCl was used as an added salt, melted at 850, 900, and 950°C to act as a solvent in the reaction processes. It was found that at 950°C, the salt melted sufficiently and therefore accelerated the subsequent nucleation and growth of barium hexaferrite nanoparticles. The barium hexaferrite nanoparticles synthesized by the salt-assisted ultrasonic spray pyrolysis method were exquisitely compared with the barium hexaferrite synthesized by conventional ultrasonic spray pyrolysis method. The particles were characterized by XRD, SEM, and TEM analyses. The salt-free barium hexaferrite obtained at 950°C revealed the presence of hematite, whereas the salt-added barium hexaferrite nanoparticles synthesized at 950°C showed the existence of only barium hexaferrite phase. The salt-added barium hexaferrite nanoparticles synthesized at 950°C showed a hexagonal plate shape, 72nm in size and with good crystallinity. The magnetic properties were investigated by vibrating sample magnetometer (VSM) at room temperature. The magnetic properties of the salt added barium hexaferrite at 950°C showed the coercivity of 5735Oe and saturation magnetization of 63.2emu/g.