Magnetics of ultrathin FePt nanoparticle films
Magnetics of ultrathin FePt nanoparticle films
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DOI：
10.1063/1.1635669
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发表时间：
2004-02-01
影响因子：
3.2
通讯作者：
Sun, SH
中科院分区：
文献类型：
--
作者：
Held, GA;Zeng, H;Sun, SH
我们提供了聚合物介导的、自组装的4纳米FePt纳米颗粒薄膜的磁化数据，其厚度在1到4纳米颗粒层之间。在合成和沉积过程中，该组件包含弱磁性材料，其体积相当于纳米颗粒的0.5 nm外壳。在580度退火过程中，这种材料被纳入纳米粒子的磁畴中。经退火转化为铁磁性L1(0) FePt的纳米颗粒的比例随着样品厚度的变化而变化，而L1(0) FePt是磁存储应用所必需的结构；在这些退火条件下，小于4层纳米颗粒层的样品没有明显的铁磁性（300 K） L1(0)结构纳米颗粒的比例，而在由4层纳米颗粒层组成的薄膜中，不到一半的颗粒在300 K时是铁磁性的。讨论了这些观察结果的可能原因。(C) 2004年美国物理研究所。
We present magnetization data for polymer-mediated, self-assembled films of 4 nm FePt nanoparticles with thicknesses between one and four nanoparticle layers. As synthesized and deposited, the assemblies contain weakly magnetic material whose volume is equivalent to an outer 0.5 nm shell of the nanoparticles. During a 580 degreesC anneal, this material is incorporated into the magnetic domains of the nanoparticles. The fraction of nanoparticles transformed by annealing into ferromagnetic L1(0) FePt, the structure essential for magnetic storage applications, is found to vary with sample thickness; samples thinner than four nanoparticle layers show no significant fraction of ferromagnetic (at 300 K) L1(0) structured nanoparticles under these annealing conditions, while in films comprised of four nanoparticle layers, less than half of the particles are ferromagnetic at 300 K. Possible causes of these observed results are discussed. (C) 2004 American Institute of Physics.