We have fabricated magnetic granular Fe‐SiO2 solids over a wide metal volume fraction range 15%–100%. The microstructure of the samples has been characterized by using transmission electron spectroscopy, electron diffraction, and Mössbauer spectroscopy. Giant magnetic coercivity, as high as 2500 Oe, has been observed in samples with nanometer particle size. The behaviors of coercivity across the metal volume fraction range are attributed to the change of particle size and percolation effect.

Topics
Granular materials, Electron diffraction, Electron spectroscopy, Mossbauer spectroscopy, Metal oxides
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© 1988 American Institute of Physics.
1988
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