以金属炔基聚合物为前体的纳米压印光刻快速制备位元规则介质

Hard ferromagnetic L1o phase FePt nanoparticles (NPs), given their superb magnetic properties, are widely explored for their application in the next generation of magnetic data recording device - bit patterned media (BPM).Self-assembly is the most common way for depositing the FePt NPs onto a substrate for making BPM. However, self-assembly does not provide long-range order which is a requirement for nanoscale manufacturing. There is growing interest in direct nanopatterning of soft materials by nanoimprint lithography (NIL), particularly for functional polymers. NIL offers a patterning resolution of sub-5 nm over large areas with long-range order which is desirable for fabricating high-density BPM. However, it has been difficult to create BPM with FePt NPs by NIL because the mechanical rigidity of NPs makes the negative pattern of the mask difficult to be transferred directly. This new project focuses on a highly topical area in which solution-processable bimetallic polymers consisting of Fe and Pt atoms or blends of two individual metallopolymers consisting of each metal center will be developed which can combine the merits of both hard magnetic FePt NPs and NIL to realize a rapid one-step fabrication of nanopatterned arrays of FePt NPs over large areas for BPM at low cost. The concept can also be applied to other hard magnetic metal alloy NPs such as CoPt, Co3Pt and SmCo5. Such new approach can simplify the manufacturing procedure of BPM. Heterobimetallic block-copolymer NIL will also be investigated as a viable technique for high-density BPM. This will greatly strengthen the competitive edge of next generation magnetic recording as a simpler technology over the other semiconductor data storage technologies.

硬铁磁L1o相FePt合金纳米粒子（NPs）由于其优越的磁性特性，被广泛研究和应用在下一代磁数据记录介质"位元规则介质（BPM）"中。FePt合金BPM通常是将FePt NPs沉积到基质上通过自组装方法制得。但是自组装制备方法难以得到长程有序的结构，无法满足纳米级制造的要求。通过纳米压印光刻（NIL）直接纳米阵列化软物质（特别是功能聚合物）是必然的趋势。NIL可提供5 nm以下的大面积阵列化，因此适合制作高密度BPM。然而通过NIL直接压印FePt NPs制作BPM比较困难，因为NPs的机械刚性使得它难以直接复制模具上的反样阵列。本项目拟合成含Fe和Pt的溶液可处理金属聚合物，结合硬磁FePt NPs和NIL的优点，发展低成本快速一步制作大面积FePt NPs的纳米级阵列并用作BPM，并且将该方法应用至其他硬磁的NPs。同时还将研究双金属嵌段共聚物的自组装及其在高密度BPM制作中的应用。

磁性合金纳米粒子，特别是铁铂、铁钯、钴铂等类型的纳米粒子，被视为是下一代开发超高密度磁存储系统的替代材料。本项目我们开发了一种以有机金属配合物作为前驱体一步热解制备面心四方相铁铂合金纳米粒子，并成功将该方法用于制备铁钯、钴铂、铁铜、铁镍、镍铂合金纳米粒子及铁、钴、镍、铂纳米粒子。通过调整分子结构或优化热解条件，不仅将磁性合金纳米粒子的的磁矫顽力大大提高至3.6 T，初步总结了热解条件对纳米粒子尺寸和性能的影响，而且通过对比小分子和聚合物前驱体表明分子间作用力更强的小分子配合物热解后易于形成尺寸较大的纳米粒子，通过调变聚合物前驱体中金属中心负载量可以进而调控纳米粒子的尺寸，这些研究成果为后续研究的深入开展奠定了坚实基础。此外，金属聚合物前驱体具有较好的溶液加工性，我们借助纳米压印技术可以快速制备大面积有序纳米阵列，热解后得到磁性纳米粒子组成的阵列，在磁力显微镜显现出明显的信号，可用于位元规则介质研究其磁存储性能。我们还通过嵌段共聚物自组装制备了超高密度的规则点阵，大大提高了其存储密度。我们还进一步将自组装和纳米压印技术结合在一起，对具有自组装性能的铁铂、铁钯配合物进行压印，成功制备了规则的自组装有序形貌。上述初步的研究成果已发表论文18篇，并有5篇文章正在投稿或者准备投稿。培养博士研究生4名，其中3名已毕业。