Optimization of magnetic properties in fast consolidated SrFe₁₂O₁₉nanocrystallites

Abstract

The degree of alignment and its influence on the coercive force in SrFe12O19 crystallites consolidated by SPS.

Alignment of strontium hexaferrite, by cold compaction of anisotropic non-magnetically interacting crystallites

“…This example clearly demonstrates the superlative magnetic performance obtained by SPS methods; however, the process reported herein surpassed that of the cold compacted powders aligned by magnetic field (H0G100 M r / M s of 0.83(1)) and approached closer to the magnetic capabilities of the SPS compacted strontium hexaferrite. Later optimisation of precursor particle size and SPS compaction conditions led to bettering of the magnetic figures of merit, M. Stingaciu et al 11 achieving an M r / M s of 0.93(2) without using an applied magnetic field.…”

“…A novel method avoids applying a magnetic field, but successfully aligns the crystallites through simultaneous use of high temperature and pressure employing either induction pressing or spark plasma sintering to offer excellent figures of merit reflected by the energy product ( BH max ) and hysteresis loop squareness ( M r / M s ). 9–14 During the compaction, the temperatures exceed the Curie temperature of the magnetic crystallites. The logic of heating beyond the Curie temperature is to overcome the magnetic interaction between the crystallites hindering bulk magnetic alignment due to magnetic short circuiting.…”

Novel Magnetic Inorganic Composites: Synthesis and Characterization

“…It is known that the structural and magnetic properties of SrFe 12 O 19 particles may change depending on the specific synthesis route [ 41 , 42 , 43 ]. Therefore, we have carried out a characterization of the commercial Sr hexaferrite particles used to prepare the composite geopolymer samples.…”

The sintering behavior of ellipsoidal particles

“…The reason for this is most likely that although it is easy to add pore former particles to a powder compact or to sieve the powder before sintering to control the particle size distribution, the shape of powder particles is not as easy to control. However, with increasingly advanced powder production techniques, complex‐shaped ceramic powder particles can now be produced, 14 and thus, it is scientifically interesting to understand how exactly the particle shape influences sintering behavior and microstructural properties.…”