The immiscibility of InAlN ternary alloy

Area of Science:

• Materials Science
• Solid State Physics
• Thermodynamics

Background:

• Indium Aluminum Nitride (InAlN) is a ternary alloy with tunable properties.
• Understanding InAlN immiscibility is crucial for controlled material synthesis and device fabrication.

Purpose of the Study:

• To investigate the immiscibility of InAlN ternary alloy.
• To determine appropriate concentration regions for epitaxial growth.
• To analyze the influence of different substrates on InAlN stability.

Main Methods:

• Utilized two thermodynamic models: valence force field and regular solution model.
• Calculated spinodal and binodal curves for InAlN.
• Incorporated mismatch strain into Gibbs free energy calculations.

Main Results:

• Determined spinodal and binodal curves, revealing InAlN immiscibility.
• Identified an InN solubility of approximately 10% at 1000 K.
• Found that substrates like Si, Al2O3, InN, GaN, and AlN stabilize InAlN, reducing the upper critical solution temperature.
• Recommended InN and GaN for In-rich InAlN, and AlN and GaN for Al-rich InAlN.

Conclusions:

• The study provides critical insights into InAlN phase diagrams and growth parameters.
• Substrate selection significantly impacts InAlN stability and composition.
• InN, GaN, AlN, Si, and Al2O3 are identified as potential substrates for specific InAlN compositions and applications.