Studies of quasicrystals and their approximants

准晶体及其近似晶体的研究

• 批准号: 105749-2012
• 负责人: Stadnik, Zbigniew
• 金额: $ 1.46万
• 依托单位: University of Ottawa
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2012
• 资助国家: 加拿大
• 起止时间: 2012-01-01 至 2013-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=507302
• 关键词: Studies; quasicrystals; their; approximants

Advances in condensed matter physics often require the discovery and development of new materials that extend or challenge the current understanding. This proposal addresses both the synthesis of new materials and the investigation of their physical properties. The proposal is concerned with one specific class of materials that are of current interest, namely quasicrystals. Discovered in 1984, quasicrystals are a new form of solid that differs from the two other forms, crystalline and amorphous, by possessing a new type of long-range order, called quasiperiodicity, and noncrystallographic orientational order associated with classically forbidden fivefold, eightfold, tenfold, and twelvefold symmetry axes. One of the central problems in condensed matter physics is determining whether quasiperiodicity leads to novel physical properties which are significantly different from those of crystalline and amorphous materials. This proposal will attempt to discover such novel properties by experimentally answering four outstanding questions of the physics of quasicrystals. What types of long-range quasiperiodic magnetic order are realized in quasicrystals? Is the predicted fine structure of the electronic density of states realized in quasicrystals? Are the extremely large values of the electrical resistivity and its nonmetallic temperature dependence the intrinsic properties of quasicrystals? Is theory capable of predicting new quasicrystals with specific physical properties? This proposal will address these four outstanding questions via the synthesis of several families of new quasicrystals and corresponding crystalline approximants and the investigation of their magnetic, electronic structure, and electronic transport properties with an array of modern experimental techniques. The end product of this proposal will be a much clearer and more complete understanding of the basic physical properties of these new materials, that may possibly lead to finding industrial applications of quasicrystals. In addition, a dozen highly qualified personnel will acquire a range of practical synthesis and measurement related skills that will help them to find employment in the high-technology sector of Canadian industry or in academia.

凝聚态物理的进步通常需要发现和开发新材料，以扩展或挑战当前的理解。本提案既涉及新材料的合成，也涉及其物理性质的研究。该提案涉及当前感兴趣的一类特定材料，即准晶体。准晶体发现于1984年，是一种不同于晶体和非晶两种其他形态的新型固体形态，它具有一种称为准周期性的新型长程秩序，以及与经典禁止的五倍、八倍、十倍和十二倍对称轴相关的非晶体取向秩序。凝聚态物理的核心问题之一是确定准周期性是否会导致与晶体和非晶态材料明显不同的新物理性质。本提案将尝试通过实验回答准晶体物理学的四个突出问题来发现这些新特性。在准晶体中实现了哪些类型的长程准周期磁序？准晶体中是否实现了所预测的态电子密度的精细结构？电阻率及其非金属温度依赖性的极大值是准晶体的固有性质吗？理论是否能够预测具有特定物理性质的新准晶体？本提案将通过合成几个新的准晶体家族和相应的晶体近似物，并利用一系列现代实验技术研究它们的磁性、电子结构和电子输运性质，来解决这四个悬而未决的问题。这项提议的最终结果将是对这些新材料的基本物理性质有一个更清晰、更完整的了解，这可能会导致发现准晶体的工业应用。此外，十几名高素质人员将获得一系列实用的综合和测量相关技能，这将有助于他们在加拿大工业的高技术部门或学术界找到工作。