| 摘要 |
PURPOSE:To shorten chain length by a method wherein chain magnetic metal ultrafine particles are placed in a fluid medium under low temperature and then subjected to shocks such as vibrations. CONSTITUTION:A number of chain magnetic metal ultrafine particles obtained by an in-gas evaporation technique and having a chain length of ca. 1mum, such that Fe-Co alloy ultrafine particles with grain size of 0.02-0.03mum are linked in the number of several tens, are applied into liquid ethanol within a rotary drum in amount of 50g/l, the ethanol being cooled down to -65 deg.C with dryice. Then, the rotary drum is rotated at a high speed of 3,000rpm, causing the chain ultrafine particles to undergo vibrations or shocks such as agitations under low temperature. As a result, the chains are disconnected and the chain length is stortened less than 0.2mum as shown in the figure. |
