Chemistry Nexus

Abstract:
The melting behavior of Ge nanocrystals embedded within SiO₂ is evaluated using in situ transmission electron microscopy. The observed melting-point hysteresis is large (±17%) and nearly symmetric about the bulk melting point. This hysteresis is modeled successfully using classical nucleation theory without the need to invoke epitaxy.¹

References

Scientists at the Lawrence Berkeley National Laboratory in California, USA, have discovered that nanocrystals of germanium embedded in silica glass don’t melt until the temperature rises almost 200 degrees Kelvin above the melting temperature of germanium in bulk.¹ What’s even more surprising, these melted nanocrystals have to be cooled more than 200 K below the bulk melting point before they resolidify.