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Enge Wang

Publications and source records attributed to Enge Wang.

5 recordsLinked to original sources
PubMed2006

Multiwall carbon nanotubes made of monochirality graphite shells.

A multiwall carbon nanotube (MWCNT) consists of several or many concentric carbon shells, each of which could be metallic or semiconducting. Both theoretical predictions and experimental results suggest that MWCNTs have exotic electronic structures and intriguing transport properties, which are highly dependent on chirality of each shell. However, the structural defects and the random distribution of chirality of each concentric graphitic shell make the MWCNTs difficult for basic research and technological applications. Thus far, it is still a challenge to get the high crystalline MWCNTs with limited atomic conformation. Here, we report the synthesis of high crystalline MWCNTs made of monochirality graphite shells by a low-temperature chemical vapor deposition (CVD) process in plasma environment. Structural analysis, carried out by transmission electron microscopy (TEM) image and electron diffraction methods, reveal that the MWCNTs are well-crystallized and that most of them have nearly identical chiralities.

Journal Article↗
PubMed2004

First principles calculation of anomalous Hall conductivity in ferromagnetic bcc Fe.

We perform a first principles calculation of the anomalous Hall effect in ferromagnetic bcc Fe. Our theory identifies an intrinsic contribution to the anomalous Hall conductivity and relates it to the k-space Berry phase of occupied Bloch states. This dc conductivity has the same origin as the well-known magneto-optical effect, and our result accounts for experimental measurement on Fe crystals with no adjustable parameters.

Journal Article↗
PubMed2003

Tubular graphite cones.

We report the synthesis of tubular graphite cones using a chemical vapor deposition method. The cones have nanometer-sized tips, micrometer-sized roots, and hollow interiors with a diameter ranging from about 2 to several tens of nanometers. The cones are composed of cylindrical graphite sheets; a continuous shortening of the graphite layers from the interior to the exterior makes them cone-shaped. All of the tubular graphite cones have a faceted morphology. The constituent graphite sheets have identical chiralities of a zigzag type across the entire diameter, imparting structural control to tubular-based carbon structures. The tubular graphite cones have potential for use as tips for scanning probe microscopy, but with greater rigidity and easier mounting than currently used carbon nanotubes.

Journal Article↗