By Roland Piquepaille
A news release from the University of Toronto (U of T) says that a team of chemists has successfully captured images of atoms during the melting of aluminum.Chemists at the University of Toronto have captured atom-scale images of the melting process-revealing the first images of the transition of a solid into a liquid at the timescale of femtoseconds, or millionths of a billionth of a second.
The result is an unprecedented "movie" detailing the melting process as solid aluminum becomes a liquid. This new study, led by Professor R. J. Dwayne Miller of the Departments of Chemistry and Physics, received the prestigious cover position of the Nov. 21 issue of Science.
Here is this cover of Science (don't forget to purchase a copy) (Credit: Brad Siwick, U of T).
Femtoseconds are pretty small time intervals. How did they do a movie?
Since no camera shutter can open and close at the femtosecond time scale, the team built a special system using a laser and an electron gun inside a vacuum chamber. The energy of the laser's blast superheated small sections of the aluminum to over 1,000 degrees Celsius, exceeding the metal's melting point of 660 degrees Celsius.
Can this be useful for you? Probably not. But these chemists think they have a new valuable tool which will allow them to make atomic movies of other chemical reactions.
"It is one of the dreams of chemistry to be able to actually watch that as it happens, and we now have a technique that lets us do that," says Jason Dwyer, a graduate student in Miller's laboratory and a co-author of the paper.
Here is the abstract of this paper published by Science, "An Atomic-Level View of Melting Using Femtosecond Electron Diffraction."
We used 600-femtosecond electron pulses to study the structural evolution of aluminum as it underwent an ultrafast laser
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