Crystallization Instead of Amorphization in Collision Cascades in Gallium Oxide

Area of Science:

• Materials Science
• Solid-State Physics
• Crystallography

Background:

• Solid disordering typically results in amorphization.
• Polymorph transitions can maintain solid-state periodicity via atomic rearrangements.
• Far-from-equilibrium conditions, like collision cascades, involve kinetically limited atomic rearrangements.

Purpose of the Study:

• To investigate crystallization instead of amorphization in gallium oxide (Ga2O3) collision cascades.
• To determine the disorder threshold for the irreversible β→γ polymorph transition in Ga2O3.
• To explain the kinetic preference for the higher-energy γ polymorph.

Main Methods:

• Analysis of atomic collision cascades in gallium oxide (Ga2O3).
• Determination of the disorder threshold for polymorph transitions.
• Investigation of atomic migration kinetics during postcascade processes.

Main Results:

• Identified the disorder threshold for the irreversible β→γ polymorph transition in Ga2O3.
• Demonstrated that the Ga sublattice kinetically favors a γ-like configuration upon reaching the disorder threshold.
• Showcased that this transition requires less Ga atom migration for lattice site occupation postcascade.

Conclusions:

• The study provides a consistent explanation for crystallization over amorphization in Ga2O3 collision cascades.
• Kinetic limitations drive the Ga sublattice towards the higher-energy γ polymorph.
• The findings offer a predictive framework for multipolymorph fabrication.