Molecular spintronic action confirmed in nanostructureOctober 13, 2006Researchers at the National Institute of Standards and Technology (NIST) have made the first confirmed "spintronic" device incorporating organic molecules, a potentially superior approach for innovative electronics that rely on the spin, and associated magnetic orientation, of electrons. The physicists created a nanoscale test structure to obtain clear evidence of the presence and action of specific molecules and magnetic switching behavior. Whereas conventional electronic devices depend on the movement of electrons and their charge, spintronics works with changes in magnetic orientation caused by changes in electron spin (imagine electrons as tiny bar magnets whose poles are rotated up and down). Already used in read-heads for computer hard disks, spintronics can offer more desirable properties-higher speeds, smaller size-than conventional electronics. Spintronic devices usually are made of inorganic materials. The use of organic molecules may be preferable, because electron spins can be preserved for longer time periods and distances, and because these molecules can be easily manipulated and self-assembled. However, until now, there has been no experimental confirmation of the presence of molecules in a spintronic structure. The new NIST results are expected to assist in the development of practical molecular spintronic devices. The experiments, described in the October 9 issue of Applied Physics Letters,* used a specially designed nanoscale "pore" in a silicon wafer. A one-molecule-thick layer of self-assembled molecules containing carbon, hydrogen and sulfur was sandwiched in the pore, between nickel and cobalt electrodes. The researchers applied an electric current to the device and measured the voltage levels produced as electrons "tunneled" through the molecules from the cobalt to the nickel electrodes. (Tunneling, observed only at nanometer and atomic dimensions, occurs when electrons exhibit wave-like properties, which permit them to penetrate barriers.) The pore structure stabilized and confined the test molecules and enabled good molecule-metal contacts, allowing the scientists to measure accurately temperature-dependent behavior in the current and voltage that confirm electron tunneling through the molecular monolayer. Some electrons can lose energy while tunneling, which corresponds to vibration energies unique to the chemical bonds within the molecules. The NIST team used this information to identify and unambiguously confirm that the assembled molecules remain encapsulated in the pore and are playing a role in the device operation. In addition, by varying the magnetic field applied to the device and measuring the electrical resistance, the researchers identified magnetic switching in the electrodes from matching to opposite polarities. National Institute of Standards and Technology (NIST) |
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| Related Spintronic Current Events and Spintronic News Articles Multiferroics -- making a switch the electric way Multiferroics are materials in which unique combinations of electric and magnetic properties can simultaneously coexist. UBC researchers put a new spin on electrons In the first demonstration of its kind, researchers at the University of British Columbia have controlled the spin of electrons using a ballistic technique--bouncing electrons through a microscopic channel of precisely constructed, two-dimensional layer of semiconductor. Keep On Spinning By controlling the collective spin state of highly mobile electrons in semiconductors, researchers in the Materials Sciences Division (MSD) at the U.S. Department of Energy's Lawrence Berkeley National Laboratory have taken a major step forward in the technology of spintronics. SPRING "BLOCKBUSTER" MOVIE NOW SHOWING: Berkeley Scientists Produce First Live Action Movie of Individual Carbon Atoms in Action Science fiction fans still have another two months of waiting for the new Star Trek movie, but fans of actual science can feast their eyes now on the first movie ever of carbon atoms moving along the edge of a graphene crystal. Spin-polarized electrons on demand Many hopes are pinned on spintronics. In the future it could replace electronics, which in the race to produce increasingly rapid computer components, must at sometime reach its limits. Different from electronics, where whole electrons are moved (the digital "one" means "an electron is present on the component", zero means "no electron present"), here it is a matter of manipulating a certain property of the electron, its spin. Spin-polarized electrons on demand Many hopes are pinned on spintronics. In the future it could replace electronics, which in the race to produce increasingly rapid computer components, must at sometime reach its limits. Neutron researchers discover widely sought property in magnetic semiconductor Researchers working at the National Institute of Standards and Technology (NIST) have demonstrated for the first time the existence of a key magnetic-as opposed to electronic-property of specially built semiconductor devices. Spinning into the future of data storage Scientists from Queen Mary, University of London have improved their understanding of the inner workings of our computers and mp3 players, thanks to an exciting new field of research called 'organic spintronics'. New invention that could change design of future memory storage devices A research team at Singapore A*STAR's Data Storage Institute (DSI) has invented a new phase change material that has the potential to change the design of future memory storage devices. Discovery by UC Riverside physicists could enable development of faster computers Physicists at UC Riverside have made an accidental discovery in the lab that has potential to change how information in computers can be transported or stored. Dependent on the "spin" of electrons, a property electrons possess that makes them behave like tiny magnets, the discovery could help in the development of spin-based semiconductor technology such as ultrahigh-speed computers. More Spintronic Current Events and Spintronic News Articles |
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