在液晶晶体中磁性血小板悬浮中的铁磁性
Alenka Mertelj1, Darja Lisjak1, Miha Drofenik2
1J. Stefan Institute, SI-1000 Ljubljana, Slovenia.
Nature
|December 17, 2013
概括
研究人员使用铁磁纳米粒子在液晶中实现了室温铁磁排序. 这一突破为磁光学设备提供了新的可能性,通过控制最小磁场的磁化来控制磁化.
科学领域:
- 软物质物理学 软物质物理学
- 材料科学 材料科学 材料科学
- 磁力学 磁力学 是一种
背景情况:
- 铁磁-阴性液晶悬浮物在几十年前就在理论上提出了.
- 自发磁化的实验实现一直是具有挑战性的.
- 之前的系统表现出偏磁性,而不是真正的铁磁性,没有外部场.
研究的目的:
- 在液晶中实验性地实现和表征宏观铁磁相.
- 研究粒子形状和相互作用在形成铁磁秩序中的作用.
- 探索磁光器件的潜在应用.
主要方法:
- 纳米尺寸的铁磁血小板悬浮在阴性液晶中.
- 从同位素相控制冷却 (灭) 来诱导订单.
- 具有和没有外部磁场的磁性属性的表征.
主要成果:
- 在从同位素相冷却后实现铁磁排序.
- 观察到具有相反磁化状态的多域样本,没有磁场.
- 创建的单域样本可以通过磁场逆转来切换.
- 证明了属性来自于无极弹性和磁性双极相互作用.
结论:
- 在这些系统中,纳米粒子形状和阴性相互作用是室温铁磁性的关键.
- 由此产生的铁磁流体对非常低的磁场有反应.
- 新型磁光器件存在潜在的应用.
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