William Marsh Rice University

Jun Lou

Pulickel Madhavapanicker Ajayan

Yang Lu

Zheng Liu

Cheng Peng

Yongjie Zhan

Yogeeswaran Ganesan

Sina Najmaei

In some embodiments, the present disclosure pertains to methods of growing chalcogen-linked metallic films on a surface in a chamber. In some embodiments, the method comprises placing a metal source and a chalcogen source in the chamber, and gradually heating the chamber, where the heating leads to the chemical vapor deposition of the chalcogen source and the metal source onto the surface, and facilitates the growth of the chalcogen-linked metallic film from the chalcogen source and the metal source on the surface. In some embodiments, the chalcogen source comprises sulfur, and the metal source comprises molybdenum trioxide. In some embodiments, the growth of the chalcogen-linked metallic film occurs by formation of nucleation sites on the surface, where the nucleation sites merge to form the chalcogen-linked metallic film. In some embodiments, the formed chalcogen-linked metallic film includes MoS.

Growth methods for controlled large-area fabrication of high-quality graphene analogs

In various embodiments, methods for synthesizing single-crystalline zero-valent metal nanorings, such as single-crystalline copper nanorings, are described herein. The methods include providing a solution containing a metal cation, a complexing agent bound to the metal cation, thereby forming a metal complex that is at least partially soluble in the solution, and a reducing agent operable for reducing the metal complex to a zero-valent metal and then heating the solution for a sufficient time and at a sufficient temperature until zero-valent metal nanorings form. The solution may be an aqueous solution in an embodiment. Single-crystalline metal nanorings produced by the methods described herein may have a diameter less than about 100 &#x3bc;m and a wall thickness between about 10 nm and about 500 nm.

Single-crystalline metal nanorings and methods for synthesis thereof

The present disclosure describes micromechanical devices and methods for using such devices for characterizing a material's strength. The micromechanical devices include an anchor pad, a top shuttle platform, a nanoindenter in movable contact with the top shuttle platform and at least two sample stage shuttles. The nanoindenter applies a compression force to the top shuttle platform, and the at least two sample stage shuttles move apart in response to the compression force. Each of the at least two sample stage shuttles is connected to the top shuttle platform and to the anchor pad by at least one inclined beam. Methods for using the devices include connecting a sample between the at least two sample stage shuttles and applying a compression force to the top shuttle platform. Application of the compression force to the top shuttle platform results in a tensile force being applied to the sample. Measuring a tip displacement of the nanoindenter is correlated with the sample's strength. Illustrative materials that can be studied using the micromechanical devices include, for example, nanotubes, nanowires, nanorings, nanocomposites and protein fibrils.

Micromechanical devices for materials characterization

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Houston, TX, United States of America

Jun Lou