Page "Glass" Paragraph 40

In 2004, NIST researchers presented evidence that an isotropic non-crystalline metallic phase ( dubbed " q-glass ") could be grown from the melt.

This phase is the first phase, or " primary phase ," to form in the Al-Fe-Si system during rapid cooling.

Interestingly, experimental evidence indicates that this phase forms by a first-order transition.

Transmission electron microscopy ( TEM ) images show that the q-glass nucleates from the melt as discrete particles, which grow spherically with a uniform growth rate in all directions.

The diffraction pattern shows it to be an isotropic glassy phase.

Yet there is a nucleation barrier, which implies an interfacial discontinuity ( or internal surface ) between the glass and the melt.