MAGNETIC-PROPERTIES OF GLASS-METAL NANOCOMPOSITES PREPARED BY THE SOL-GEL ROUTE AND HOT-PRESSING

Glass-metal nanocomposite powders in the systems Fe/SiO2 and Ni/SiO2 h ave been prepared by the sol-gel technique followed by reduction treat ment. Bulk nanocomposites are then fabricated by hot pressing these po wders. The metal particle diameters range from 8.9 to 14.8 nm. The mat erials show enhanced coercivities, e.g., a maximum of 82 Oe in the cas e of Ni/SiO2 and a maximum of 474 Oe in the case of Fe/SiO2 systems. T he Mossbauer spectra of Fe/SiO2 samples are comprised of a ferromagnet ic component superposed on a superparamagnetic doublet.