Crystallography and Functional Evolution of Atomically Thin Confined Nanowires

该项目涉及在单壁碳纳米管内部形成的一到四个原子厚的一维“极端纳米线”的空间和时间分辨晶体学，结构细化和功能演变-原子光滑模板，热稳定性高达1130 C。该项目还将解决纳米限制相变材料的特殊情况，这些材料在非易失性存储器和薄膜器件开发中具有潜在的实用性，既用于基本特性评估-包括新物理学的几个方面-也用于“原理证明”器件创建，用于薄膜器件的潜在开发，包括太阳能电池，化学传感器，燃料电池，电池和催化剂，所有这些都可能带来经济效益。目的和目标-预计该项目将联合收割机以下许多方面。I.合成和晶体学：将研究碳纳米管和氮化硼纳米管中横截面中的2-4个原子的少原子厚极端纳米线（EN）的3D晶体学。学生将从事Ge 2Sb 2 Te 5（GST）和一些磁性和铁电公式的研究。4D晶体学：在有史以来最小的体积尺度上解决结晶<=>玻璃转变，建立相变材料（PCM）可以研究和原则上“写入”的尺寸下限（~ 1纳米立方）。学生将在此背景下研究PCM GST。三.精炼/提纯：极端纳米线结构的纯化允许以前所未有的细节研究其功能演变，并使其物理特性适应广泛的可能应用。学生将使用这些方法精炼碳纳米管和氮化硼复合材料。薄膜/试验器械：生产和测试封装纳米线和纳米限制相变材料的各向异性薄膜中的薄膜和试验设备。电导开关特性将在MEMS风格的加热/接触TEM支架中进行原位测试，这些特性也将在简单的内部制造设备中进行“非原位”测试，以进行“原理证明”演示。这项工作的所有四个方面都需要与研究方法的新颖性的詹姆斯·赫德-休斯博士合作，对宿主材料进行光学测试和改进。该项目将在可扩展制造的实际极限下运行，研究横截面薄如单个原子的一维晶体，材料科学的“最终前沿”，以及相对于二维结构（如石墨烯或“2D”类似物）的下一个和最终最低维度。与EPSRC的战略和研究领域保持一致（见https：//www.epsrc.ac.uk/research/ourportfolio/themes/）从广义上讲，该项目解决了EPSRC的重大挑战“功能材料的纳米尺度设计”，但这些极端物体的量子尺寸尺度和非平衡结构将影响其他重大挑战，包括“新量子技术的量子物理学”和“涌现和远离平衡的物理学”。“这个学生奖学金也是由物理系授予的，以支持授予沃里克的J Sloan博士的EPSRC资助项目”原子薄纳米线的晶体学和功能演变“（即EP/R 019428/1）。

This project concerns the spatial and time resolved crystallography, structural refinement and functional evolution of one to four atom thick 1D 'Extreme Nanowires' formed inside single walled carbon nanotubes - atomically smooth templates that are thermally robust up to 1130 C. This project will also address the special case of nano-Confined Phase Change Materials, which have potential utility in Non-Volatile Memory and the development of thin film devices, both for fundamental properties evaluation - including several aspects of Novel Physics - but also for 'Proof of Principle' device creation for potential exploitation in thin film devices including solar cells, chemical sensors, fuel cells, batteries and catalysts, all of which may bring economic benefits.Aims and objectives - it is expected that this project will combine many aspects of the following. I. Synthesis and crystallography : the 3D crystallography of few-atom thick Extreme Nanowires (EN) 2-4 atoms in cross section in carbon nanotubes and also in boron nitride nanotubes will be investigated. The student will work on Ge2Sb2Te5 (GST) and some magnetic and ferroelectric formaulations.II. 4D Crystallography : Resolving crystalline <=> glass transformations at the smallest volume scale ever attempted, establishing the lower size limit (~one nanometre cubed) at which Phase Change Materials (PCM) can be investigated and, in principle 'written'. The student will investigate the PCM GST in this context. III. Refinement/Purification : Purification of Extreme Nanowire structures allowing the study of their functional evolution in unprecedented detail and the adaptation of their physical properties to a wide range of possible applications. The student will refine both carbon nanotube and boron nitride composites using these approaches.IV. Thin Films/Trial Devices: Production and testing of thin films and trial devices in anisotropic films of encapsulated nanowires and nano-confined Phase Change Materials.The conductance switching characteristics will be tested in situ in a MEMS style heating/contacting TEM holders and these properties will also be tested 'ex situ' in simple in house fabricated devices for 'proof of principle' demonstrations. All four aspects of this work will require optical testing and refinement of the host materials in collaboration with Dr. James Lloyd-HughesNovelty of the research methodologyThis project will operate at the practical limit of scalable fabrication investigating 1D crystals as thin as a single atom in cross-section, a 'Final Frontier' of materials science and the next and ultimate lowest dimension relative to two-dimensional structures such as graphene or '2D' analogues. Alignment to EPSRC's strategies and research areas (see https://www.epsrc.ac.uk/research/ourportfolio/themes/) Broadly speaking, this project addresses the EPSRC Grand Challenges 'Nanoscale Design of Functional Materials' but the quantum size scale and non-equilibrium architecture of these extreme objects will impact on other Grand Challenges, including 'Quantum Physics for New Quantum Technologies'and 'Emergence and Physics Far From Equilibrium.' This studentship was also awarded in by the Department of Physics in support of the awarded EPSRC funded project 'Crystallography and Functional Evolution of Atomically Thin Nanowires' awarded to Dr J Sloan in Warwick (i.e. EP/R019428/1)