Aimantation spontanée des ferrites

Abstract

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Comparative study of the structural and magnetic properties of two cobalt ferrite nanocrystals produced with different iron precursors

“…It is significantly lower. Note that 5k-M sat of CoF Ac is higher than that reported for bulk CoFe 2 O 4 (93.9 emu g À 1 [6]). …”

A study of nanosized magnesium ferrite particles with high magnetic moment

“…However, even for the case of bulk samples, it has been possible to obtain much larger value of magnetisation by quenching. These values were obtained by extrapolating to 0 K. Pauthenet and Bochirol [7] have reported an increase in 0 K saturation magnetisation for bulk MgFe 2 O 4 by quenching them from 1200°C (61 emu/g). Kriessman and Harrison have demonstrated a further increase in 0 K magnetisation up to 63 emu/g by quenching from 1400°C [8].…”

“…Magnesium ferrite is an interesting ferrite because of change in its properties due to thermal treatment [7,8]. There have been various reports on the enhancement of magnetisation of magnesium ferrite when quenched from higher temperatures.…”

Rock Magnetic Properties of Mafic Rocks from the Middle Valley Sedimented Rift

“…However, the principal magnetic mineral in the sills at Site 857 is nearly pure magnetite, with Curie temperature of 580°C. The spontaneous magnetization of pure magnetite at 300°C is lowered by about 20% compared to the roomtemperature value (Panthenet, 1952). Because the magnetite in the sills is in the pseudo-single-domain range, the in-situ intensity of remanent magnetization is lowered by roughly the same degree as the spontaneous magnetization (McClelland and Sugiura, 1987).…”