Carbon wires grow from tiny graphite tubes.Short chains of carbon sticking out Adj. 1. sticking out - extending out above or beyond a surface or boundary; "the jutting limb of a tree"; "massive projected buttresses"; "his protruding ribs"; "a pile of boards sticking over the end of his truck" from the ends of tiny tubes of graphite may one day form the ultimate in miniature electronic components--atom-sized sensors and probes. Scientists have found that when they send an electric charge across the graphite tubes, a more concentrated stream of electrons moves away from the carbon tails than from the tubes alone. The graphite tubes--called carbon nanotubes because of their nanometer-scale dimensions (SN: 4/3/93, p.214)--actually consist of 10 to 20 concentric tubes nested inside one another. Because they conduct electricity well, the nanotubes sparked the interest of researchers who wanted to grow them into long wires. In the Sept. 15 Science, Richard E. Smalley Noun 1. Richard E. Smalley - American chemist who with Robert Curl and Harold Kroto discovered fullerenes and opened a new branch of chemistry (born in 1943) Richard Errett Smalley, Richard Smalley, Smalley of Rice University in Houston and his colleagues describe the carbon chains pulling away from the nanotubes "in a process that resembles unraveling the sleeve of a sweater." Heating the closed, dome-shaped ends of the nanotubes with a laser caused them to open and made the edges jagged and sharp. As the tubes cooled back to room temperature, carbon chains came away from the ends like loose threads pulled taut by the electric field. Although the researchers cannot observe A type of fire control which indicates that the observer or spotter will be unable to adjust fire, but believes a target exists at the given location and is of sufficient importance to justify firing upon it without adjustment or observation. the chains directly, they believe the chains can be only 10 to 100 atoms long, says coauthor Andrew G Andrew Jonas Günsberg (born 1974), popularly known as Andrew G, is an Australian television and radio presenter who is best known as the co-host of the reality series Australian Idol. He was also the compere of Network Ten's game show The Con Test. . Rinzler of Rice. After unraveling a bit, each chain essentially hits a snag--a carbon atom Noun 1. carbon atom - an atom of carbon atom - (physics and chemistry) the smallest component of an element having the chemical properties of the element that bridges adjacent layers of the nanotube A carbon molecule that resembles a cylinder made out of chicken wire one to two nanometers in diameter by any number of millimeters in length. Accidentally discovered by a Japanese researcher at NEC in 1990 while making Buckyballs, they have potential use in many applications. . As a chain unravels from one layer, it eventually hits one of these "spot welds" and stops. Rice's group found that the intensity of the electric current coming off the carbon chains on a nanotube was a million times greater than that from a nanotube alone. They now plan to measure the energy of the emitted electrons. Because the tips of the chains are so sharp--only one atom wide--Rice thinks the electron energies should also peak sharply. This could open the way to "laser beams of electrons," Rinzler says. Though that application is far in the future, just being able to handle and manipulate the nanotubes "represents a step forward," says Hongjie Dai Professor Hongjie Dai of the Department of Chemistry at Stanford University is a leading figure in the study of carbon nanotubes. Born in China in 1966, he received a B.S. in Physics from TsingHua University, Beijing, in Physics in 1989 and a Ph.D. of Harvard University. |
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