Synthesis of single domain strontium ferrite powder by pulsed laser ablation

Abstract

Strontium hexaferrite nanoparticles have been successfully prepared from a sintered SrFe12O19 target, using pulsed excimer laser ablation and cold condensation technique. The as-condensed powders do not exhibit the same magnetic properties as the target material. However, annealing at a high temperature of 850 °C for 3 h in air followed by fast cooling yields very high coercivity of 6665 Oe, exhibiting presence of single domain particles. Vibrating sample magnetometry (VSM), scanning electron microscopy (SEM), and x-ray diffraction (XRD) techniques are used to study the magnetism, microstructure, and phase formation in the powders, respectively.

Fine Strontium Ferrite Powders from an Ethanol‐Based Microemulsion

“…The maximum iH c value of 6195 Oe obtained at 900°C for the microemulsion-derived ferrite is comparable to the highest values previously reported for fine strontium ferrite powders prepared via many other wet-chemical routes. 13,14,37,39 As already established, the intrinsic coercivity of ferrites is strongly affected by their particle/grain sizes. 7,40 At temperatures Ͻ900°C, the dominant factor for improving intrinsic coercivity with increasing calcination temperature is the development of the SrFe 12 O 19 phase, as supported by the XRD phase-analysis results shown in Fig.…”

“…FTIR spectra of the as-dried precursor derived by conventional coprecipitation and of powders calcined at various temperatures. critical size in the range 40 -60 nm 13,14,39 has been suggested for achieving maximum coercivity in SrFe 12 O 19 .…”

Magnetic properties of Sr-ferrites synthesized in molten flux

“…The Sr-ferrite powders, SrFe 12 O 19 have been synthesized by the molten salt method, having the well-developed hexagonal platelet-like morphology. The size and thickness of the platelet particle increased as the reaction temperature and time increased.…”

“…However, this production process has difficulty to form the hexagonal platelets of homogeneous composition and uniform particle distribution. The chemical co-precipitation and sol-gel method were used to prepare the hexagonal ferrite for high-density magnetic media and microwave devices [11,12]. In addition to SrCO 3 , SrSO 4 , BaCO 3 , and BaSO 4 as starting materials, the molten salt method utilizes various salts such as NaCl, KCl, Na 2 SO 4 , and Na 2 CO 3 , etc.…”

Nanoscale integration of oxides and metals in bulk 3D composites: leveraging SrFe12O19/Co interfaces for magnetic exchange coupling

“…The ideal hard phase length scale is the single domain size which maximizes coercivity. The single domain size is * 500 nm [12] for SFO, so we chose a powder with close to this average particle size. For efficient exchange coupling, dimension of the soft phase should be about twice the wall thickness of magnetic domains in the hard magnetic phase (the domain wall width is a good approximation of the exchange length [13]).…”