Three-dimensional binary superlattices of magnetic nanocrystals and semiconductor quantum dots
Three-dimensional binary superlattices of magnetic nanocrystals and semiconductor quantum dots
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DOI：
10.1038/nature01702
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发表时间：
2003-06-26
期刊：
影响因子：
64.8
通讯作者：
O'Brien, S
中科院分区：
文献类型：
--
作者：
Redl, FX;Cho, KS;O'Brien, S
合成纳米颗粒的策略的最新进展，如半导体量子点（1），磁体和贵金属簇（2）-已经能够精确控制成分，尺寸，形状（3），晶体结构（4）和表面化学。所得到的纳米级结构单元的独特性质可以在具有新的集体性质的组件中利用（2，5，6），其可以通过控制颗粒间间距和材料加工来进一步工程化。我们的研究是由新兴的超材料概念（7）-材料的性质所产生的控制相互作用的不同纳米晶体在一个组件。由于组装过程中的非定向力或流动性不足（10-14），以前的多组分超晶格组装通常会导致无定形或短程有序材料（8，9）。在这里，我们报告的PbSe半导体量子点和Fe 2 O3磁性纳米晶体的自组装成精确有序的三维超晶格。使用特定的尺寸比将磁性和半导体纳米颗粒组装成具有潜在可调光学和磁性的AB（13）或AB（2）超晶格。这种合成概念最终可以使材料对磁、电、光和机械刺激的响应得以微调（6）。
Recent advances in strategies for synthesizing nanoparticles such as semiconductor quantum dots(1), magnets and noble-metal clusters(2) - have enabled the precise control of composition, size, shape(3), crystal structure(4), and surface chemistry. The distinct properties of the resulting nanometre-scale building blocks can be harnessed in assemblies with new collective properties(2,5,6), which can be further engineered by controlling interparticle spacing and by material processing. Our study is motivated by the emerging concept of metamaterials(7) - materials with properties arising from the controlled interaction of the different nanocrystals in an assembly. Previous multi-component nanocrystal assemblies have usually resulted in amorphous or short-range-ordered materials(8,9) because of non-directional forces or insufficient mobility during assembly(10-14). Here we report the self-assembly of PbSe semiconductor quantum dots and Fe2O3 magnetic nanocrystals into precisely ordered three-dimensional superlattices. The use of specific size ratios directs the assembly of the magnetic and semiconducting nanoparticles into AB(13) or AB(2) superlattices with potentially tunable optical and magnetic properties. This synthesis concept could ultimately enable the fine-tuning of material responses to magnetic, electrical, optical and mechanical stimuli(6).