Nickel-tungsten-phosphorus (Ni-W-P) particles with an average size of ca. 200 nm were fabricated by electroless deposition (ED) on silica particles and Au seeds. For ED processes to proceed on silica surface, a thin Au shell of ca. 5nm is introduced at first for Ni-W-P to grow subsequently. TEM, SEM equipped with EDX, Vibrating Sample Magnetometer (VSM), SQUID and FT-IR were employed to characterize the as-deposited Ni-W-P nanoparticles. It is found that a less deposition temperature near 70, aC is sufficient to deposit Ni-W-P particles, in contrast to 90, aC required for the Ni-W-P deposition on planar substrates. EDX and FT-IR confirms that Au has been covalently deposited onto silica. The nickel-content in as-deposited Ni-W-P particles is around 90% by weight. The magnetization curve for the Ni-W-P particles shows no hysteresis, though nickel is known to be ferromagnetic. Magnetic properties of these Ni-W-P particles are profoundly influence on the P-contents in these particles. The Curie temperatures of these particles are around 300 K, whereas saturation magnetization ranges from 0.1 to 20 emu/g.
|出版狀態||Published - 2005|
|事件||05AIChE: 2005 AIChE Annual Meeting and Fall Showcase - Cincinnati, OH, United States|
持續時間: 2005 十月 30 → 2005 十一月 4
|Other||05AIChE: 2005 AIChE Annual Meeting and Fall Showcase|
|期間||05-10-30 → 05-11-04|
All Science Journal Classification (ASJC) codes