Sonochemistry permits extremely rapid cooling from the melt which is necessary for forming amorphous metals. Sonochemistry also functions at an extremely small scale to produce nanophase particles. If magnetic, these particles are valuable for magnetic recording media, manufacture of permanent magnets, and other uses. The nanophase particles agglomerate, however, which limits their utility for these magnetic applications. To keep the particles isolated, we extract the particles from the n-alkane reaction solvent in a polar solvent and cast the extracted particles with a polymer, such as polyvinylpyrrolidone.