The National Science Foundation has awarded $1.65 million to a project led by Washington University in St. Louis physicist Ken Kelton to build an electrostatic levitation chamber that will be installed at the Spallation Neutron Source in Oakridge National Laboratory.
Using neutrons as a probe, the instrument will allow scientists to watch atoms in a suspended drop of liquid as the drop cools and solidifies.
Kelton, PhD, the Arthur Holly Compton Professor in Arts & Sciences and chair of physics at Washington University, has many plans for the new instrument, but is particularly eager to see what it can tell him about a phase transition called the glass transition.
Glasses are formed when a liquid changes smoothly from a freely flowing liquid to a viscous liquid and finally to a rigid structure.
All liquids can form glasses, but some, such as liquid metals, will form a glass only when they are cooled very quickly. Liquid silica, on the other hand, will form glass even when it is cooled slowly. Glassmakers exploit this slow transition to form silicate glass into intricate objects, such as vases and wine glasses.
Even though glasses have been known and used for centuries (the earliest record of glass production — on clay tablets discovered in Mesopotamia — is nearly 4000 years old), scientists still don’t fully understand the physics underlying glass formation.
In fact, Nobel laureate Philip Anderson has called the glass transition “the deepest and most interesting unsolved problem in solid-state research.”