Depth resolved properties of nanoscopic heterostructures using ß-NMR

当材料不是通过形成化合物而是形成异质结构（在最简单的情况下，一种材料的薄膜在另一种材料的衬底上）而组合时，所得性质可能与每种纯块状起始材料的性质显著不同。这种“超材料”在电子和传感器中有重要的应用，新开发的超材料可以具有前所未有的特性，这些特性可能构成量子计算机或自旋电子学等全新技术的基础。以类似的方式，材料的性质在自由表面处不同，例如，在表面重构中，表面处的原子的晶体结构不同于块体的简单截断的晶体结构。这种影响可以（而且通常确实）在地表以下传播。因此，自由表面附近的超材料和晶体的性质是深度相关的。人们对这种现象知之甚少，主要是因为可用的深度分辨技术很少。该提案旨在使用加拿大国家粒子和核物理实验室TRIUMF的低能β探测核磁共振技术，作为固体材料的新深度分辨（纳米尺度，即十亿分之一米）实验探测器，解决纳米结构超材料中的磁性和超导性等基本和实际问题。离子在固体中的扩散运动是另一个实际上重要的性质（例如在固态电化学电池中），其在界面或自由表面附近被改变（并且依赖于深度）。该提案还旨在研究在这种情况下分离的探针离子的扩散。

When materials are combined, not through formation of a compound, but instead into a heterostructure (in the simplest instance, a thin film of one material on a substrate of another) the resulting properties may differ substantially from those of each of the pure bulk starting materials. Such "metamaterials" have important applications in electronics and sensors, and newly developed metamaterials can have unprecedented properties which may form the basis of entirely new technologies, such as quantum computers or spintronics. In a similar way, the properties of materials differ at a free surface, for example, in surface reconstruction, the crystal structure of atoms at the surface is different from that of a simple truncation of the bulk. Such effects can (and generally do) propagate below the surface. Thus, the properties of metamaterials and crystals near a free surface are depth dependent. Remarkably little is known about such phenomena, mainly because very few depth-resolved techniques are available. This proposal aims to use the technique of low energy beta detected nuclear magnetic resonance at TRIUMF, Canada's National Lab for Particle and Nuclear Physics, as a new depth-resolved (at the nanometer scale, i.e. one billionth of a meter) experimental probe of solid materials, addressing fundamental and practical questions in, for example, magnetism and superconductivity in nanoscopically structured metamaterials. The diffusive motion of ions in solids is another practically important property (for instance in solid state electrochemical batteries) that is modified (and depth-dependent) in the vicinity of an interface or free surface. The proposal also aims to study diffusion of the isolated probe ions in this context.