自组装的FePt纳米晶体具有很大的强制性:降低fcc-to-L1(0) 温度顺序
Laudemir Carlos Varanda1, Miguel Jafelicci
1Laboratory of Magnetic Materials and Colloids, Department of Physical Chemistry, Institute of Chemistry, Universidade Estadual Paulista (UNESP), P.O. Box 355, 14801-970 Araraquara, São Paulo, Brazil.
Journal of the American Chemical Society
|August 24, 2006
概括
研究人员开发了一种新方法来合成FePt纳米粒子. 这一过程降低了订单温度,产生具有高强迫性的铁磁纳米晶体,而不会受到颗粒损伤.
科学领域:
- 材料科学 材料科学 材料科学
- 纳米技术 纳米技术
- 磁力学 磁力学 是一种
背景情况:
- 铁 (FePt) 纳米粒子对于高密度磁性存储介质至关重要.
- 达到有序的L1(0) 阶段需要高的回火温度,往往导致粒子凝聚和自我组装结构的损失.
- 控制纳米粒子组成和相变化是优化磁性质的关键.
研究的目的:
- 为了合成单分散的Fe(55) Pt(45) 纳米粒子.
- 为了将这些纳米粒子自组装成有序的阵列.
- 开发一种合成路径,降低面中心四角形 (fct) L1(0) 阶段的订制温度,最大限度地降低结构降解并保持磁性.
主要方法:
- 采用修改过的聚合物工艺进行纳米粒子合成.
- 实现了自组装成六角密封和立方阵列.
- 在550°C30分钟内采用化,以诱导面中心立方体 (fcc) 到面中心四角形 (fct) 的相变.
主要成果:
- 成功合成了4.0±0.2纳米Fe(55) Pt(45) 纳米粒子,并改善了组合控制.
- 经过修改的合成路径将fcc-to-fct订单温度降低了30-50°C,没有添加剂.
- 与传统方法相比,化纳米颗粒表现出具有高强制性的铁磁性行为 (H ((C) = 11.1 kOe),并减少凝聚力.
结论:
- 修改后的聚醇工艺提供了对FePt纳米粒子合成和自我组装的增强控制.
- 降低排序温度有效地防止粒子凝聚,并在相位转换过程中保持位置顺序.
- 这种方法可以产生高性能铁磁FePt纳米晶体,适用于先进的磁性应用.
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