Matter Adsorbed on Nanoscale Devices

技术摘要：该项目将以单层原子或简单分子的形式测量物质的性质和相，这些原子或简单分子沉积在一个、两个或捆绑的单壁碳纳米管上。利用已经设计、制造和测试的非常敏感的单悬浮和双悬浮纳米管机械振荡器，在兆赫兹范围内振动，作为极其敏感的质量平衡（在几个原子的水平上），该项目将测量从He同位素到Xe原子的质量吸附等温线，以及有趣的氢、氮和氧分子。由于悬浮纳米管的原始表面和非常低的质量，本项目将精确地绘制相边界，测量二维（2d）物质的临界和三临界参数，研究二维到一维（1d）的交叉行为作为温度和吸附质量的函数，获得经典和量子力学单层的优异吸附热值，并研究表面吸附对衬底电子性能的影响。这可能会导致新的超灵敏物质特异探测器的制造。对于那些感兴趣的系统，该项目将通过使用法国格勒诺布尔的设施进行国际合作，测量吸附剂的晶体结构和声子光谱。参与的研究生和本科生将接受当代电子、热力学、扫描和散射测量技术的培训，这些技术都适用于纳米技术。非技术摘要。只有一层厚度的原子或分子薄膜（称为“二维”）比常规的“三维”物质在更低的温度下凝结和凝固。原子线（极端的“一维”情况）即使一直降到绝对零度，也不会凝结或凝固。为了探索这一令人着迷的极限，这个项目将测量物质的性质，这些物质的形式是被限制在一个或两个单独的单壁碳纳米管表面的单层原子或简单分子。我们已经设计、制造和测试过的纳米管机械振荡器作为极其敏感的质量天平（它只能检测到表面上的几个原子），该项目将测量许多不同温度下的质量沉积，原子范围从氦（低质量）的同位素到氙（大质量），以及氢、氮和氧的分子形式，这是非常实际的兴趣。该项目还将研究它们对纳米管中电子运动的影响，这可能会导致新的、更敏感的和气体特异性的探测器。对于某些系统，该项目还将通过使用法国格勒诺布尔的设施进行国际合作，测量吸附物的排列和振动谱。该项目涉及研究生和本科生，他们正在接受在广泛温度范围内适用于纳米技术的当代电子、热力学、扫描和散射测量技术的培训。

Technical AbstractThis project will measure the properties and phases of matter in the form of a single layer of atoms or simple molecules deposited on one, two, or bundled single-walled carbon nanotubes. With already designed, constructed and tested very sensitive one- and two-suspended nanotube mechanical oscillators vibrating in the upper megahertz range to act as extremely sensitive mass balances (at the level of a few atoms), this project will measure mass adsorption isotherms using atoms from the He isotopes to Xe, and the interesting molecules of hydrogen, nitrogen and oxygen. Due to the pristine surface and very low mass of the suspended nanotubes, this project will map accurately phase boundaries, measure critical and tri-critical parameters of two-dimensional (2d) matter, study 2d to one-dimensional (1d) crossover behavior as a function of temperature and adsorbed mass, obtain excellent values of heats of adsorption for both classical and quantum mechanical monolayers, and study the effect of surface adsorbates on the electronic properties of the substrate, which may lead to the fabrication of new ultra sensitive matter specific detectors. For those systems of interest, this project will measure the crystalline structure and the phonon spectrum of the adsorbates through an international collaboration using the facilities in Grenoble, France. Graduate and undergraduate students participating are being trained in contemporary electronic, thermodynamic, scanning and scattering measurement techniques, all applicable to nanotechnology. Non Technical Abstract.Films of atoms or molecules just one layer thick (said to be "two-dimensional") condense and solidify at lower temperatures than regular "three-dimensional" matter. Lines of atoms (the extreme "one-dimensional" case) are expected not to condense or solidify even all the way down to absolute zero of temperature. To explore this fascinating limit, this project will measure the properties of matter in the form of a single layer of atoms or simple molecules confined to the surface of one or two individual single-walled carbon nanotubes. With nanotube mechanical oscillators which we have already designed, constructed and tested acting as extremely sensitive mass balances (which can detect just a few atoms on the surface), this project will measure mass deposition at many different temperatures, with atoms ranging from the isotopes of helium (low mass) to xenon (large mass), and the molecular forms of hydrogen, nitrogen and oxygen which are of great practical interest. This project also will study their effect on the electrons moving in the nanotubes, which may lead to new, more sensitive and gas-specific detectors. For certain systems this project will also measure the arrangement and the vibrational spectrum of the adsorbates through an international collaboration using facilities in Grenoble, France.This project involves graduate and undergraduate students who are being trained in contemporary electronic, thermodynamic, scanning and scattering measurement techniques applicable to nanotechnology, over a wide range of temperatures.