Surface treatment of ferromagnetic nanoparticle-assembly by UV irradiation with ozone
- 作者：Mu-Pei Chen ; Kazuya Kuroishi and Yoshitaka Kitamoto
- 关键词：Fe– ; Pt ; Nanoparticle ; Self-assembly ; Ultraviolet-ozone treatment
- 刊名：Electrochimica Acta
- 出版年：2005
- 期刊代码：30_00134686
- 类别：ch
- 出版时间：2005
- 卷：51
- 期：5
- 页码：860-863
- 文件大小：261 K
摘要
Fe–Pt nanoparticles of 3.5 nm in average particle diameter are obtained with the simultaneous chemical reduction of platinum acetylacetonate and the thermal decomposition of iron pentacarbonyl. Because the as-synthesized particles are superparamagnetic at room temperature, they must be transformed to L10 ordered phase by annealing at temperatures above 773 K to apply to high-density magnetic recording media. However, the annealing at such high temperatures induces the coalescence and inter-particle sintering. In the present paper, to solve the problem caused by the annealing, we use ultraviolet-ozone treatment to modify particle surface. Even after annealing at 773 K, the crystalline size is kept at 4.4 nm. Furthermore, coercivity is higher than that without the ultraviolet-ozone treatment.