3 research outputs found
Phase Transformation of GeO<sub>2</sub> Glass to Nanocrystals under Ambient Conditions
Theoretically,
the accomplishment of phase transformation requires
sufficient energy to overcome the barriers of structure rearrangements.
The transition of an amorphous structure to a crystalline structure
is implemented traditionally by heating at high temperatures. However,
phase transformation under ambient condition without involving external
energy has not been reported. Here, we demonstrate that the phase
transformation of GeO<sub>2</sub> glass to nanocrystals can be triggered
at ambient conditions when subjected to aqueous environments. In this
case, continuous chemical reactions between amorphous GeO<sub>2</sub> and water are responsible for the amorphous-to-crystalline transition.
The dynamic evolution process is monitored by using in situ liquid-cell
transmission electron microscopy, clearly revealing this phase transformation.
It is the hydrolysis of amorphous GeO<sub>2</sub> that leads to the
formation of clusters with a size of ∼0.4 nm, followed by the
development of dense liquid clusters, which subsequently aggregate
to facilitate the nucleation and growth of GeO<sub>2</sub> nanocrystals.
Our finding breaks the traditional understanding of phase transformation
and will bring about a significant revolution and contribution to
the classical glass-crystallization theories
Phase Transformation of GeO<sub>2</sub> Glass to Nanocrystals under Ambient Conditions
Theoretically,
the accomplishment of phase transformation requires
sufficient energy to overcome the barriers of structure rearrangements.
The transition of an amorphous structure to a crystalline structure
is implemented traditionally by heating at high temperatures. However,
phase transformation under ambient condition without involving external
energy has not been reported. Here, we demonstrate that the phase
transformation of GeO<sub>2</sub> glass to nanocrystals can be triggered
at ambient conditions when subjected to aqueous environments. In this
case, continuous chemical reactions between amorphous GeO<sub>2</sub> and water are responsible for the amorphous-to-crystalline transition.
The dynamic evolution process is monitored by using in situ liquid-cell
transmission electron microscopy, clearly revealing this phase transformation.
It is the hydrolysis of amorphous GeO<sub>2</sub> that leads to the
formation of clusters with a size of ∼0.4 nm, followed by the
development of dense liquid clusters, which subsequently aggregate
to facilitate the nucleation and growth of GeO<sub>2</sub> nanocrystals.
Our finding breaks the traditional understanding of phase transformation
and will bring about a significant revolution and contribution to
the classical glass-crystallization theories
Phase Transformation of GeO<sub>2</sub> Glass to Nanocrystals under Ambient Conditions
Theoretically,
the accomplishment of phase transformation requires
sufficient energy to overcome the barriers of structure rearrangements.
The transition of an amorphous structure to a crystalline structure
is implemented traditionally by heating at high temperatures. However,
phase transformation under ambient condition without involving external
energy has not been reported. Here, we demonstrate that the phase
transformation of GeO<sub>2</sub> glass to nanocrystals can be triggered
at ambient conditions when subjected to aqueous environments. In this
case, continuous chemical reactions between amorphous GeO<sub>2</sub> and water are responsible for the amorphous-to-crystalline transition.
The dynamic evolution process is monitored by using in situ liquid-cell
transmission electron microscopy, clearly revealing this phase transformation.
It is the hydrolysis of amorphous GeO<sub>2</sub> that leads to the
formation of clusters with a size of ∼0.4 nm, followed by the
development of dense liquid clusters, which subsequently aggregate
to facilitate the nucleation and growth of GeO<sub>2</sub> nanocrystals.
Our finding breaks the traditional understanding of phase transformation
and will bring about a significant revolution and contribution to
the classical glass-crystallization theories