文摘
To evaluate the self-heating effects of FeCo magnetic nanoparticles, we synthesized surfaceoxidized FeCo nanoparticles by using the co-precipitation method with the reduction reaction without any post treatments. As-synthesized FeCo nanoparticles exhibited a mean diameter of about 39 nm with an oxidized shell thickness of about 4 − 5 nm. The saturation magnetization and coercivity were found to be 172 emu/g and 268 Oe at 300 K, respectively. The heat elevation of the FeCo magnetic colloid was measured under alternating magnetic fields of 76, 102, and 127 Oe with selectable frequencies of 190, 250 and 355 kHz. The heat temperature increased up to about 45 ◦C from an initial temperature of 24 ◦C under a 127 Oe field with a frequency of 355 kHz, at which the specific absorption was about 35.7 W/g.KeywordsMagnetic nanoparticleFeCoCo-precipitationAlternating magnetic fieldColloid