To make bronze, tin flakes do a wild dance
By Peter Weiss
![](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2004/08/4304.jpg?resize=84%2C94&ssl=1)
Jitterbugging flecks of metal are challenging some prevailing ideas of how alloys form.
When deposited atop a pure copper crystal, tin atoms form into 100,000-atom rafts that scoot around madly, depositing bronze spots in their wake, physicists at Sandia National Laboratories in Livermore, Calif., have found.
So much for the long-held notion of placid patches of tin slowly trading atoms with the underlying copper to make bronze. Instead, the agitated tin scraps grab copper atoms as they scurry along, report Andreas K. Schmid and his colleagues in the Nov. 24 Science.