Thermal Boundary Characteristics of Homo-/Heterogeneous Interfaces

Area of Science:

• Materials Science
• Computational Physics
• Chemical Engineering

Background:

• Thermal boundary resistance (TBR) at solid interfaces is experimentally difficult to measure.
• Reactive interfaces can form intermediate layers, complicating thermal transport.
• Understanding interfacial phenomena is crucial for thermal management in materials.

Purpose of the Study:

• To investigate thermal boundary resistance (TBR) at reactive and non-reactive solid interfaces.
• To quantify the impact of chemical reactivity on TBR using simulations.
• To connect simulation results with phenomenological theory for interface temperature profiles.

Main Methods:

• Reactive force field Molecular Dynamics (ReaxFF MD) simulations were employed.
• Phenomenological theory (PT) was used to predict temperature discontinuities.
• Simulations compared homogeneous and heterogeneous non-reactive interfaces, and reactive Si/SiO2 interfaces.

Main Results:

• ReaxFF MD and PT confirmed continuous temperature profiles for homogeneous non-reactive interfaces and temperature jumps for heterogeneous ones.
• The TBR of a reacted Si/SiO2 interface was found to be approximately double that of a non-reactive interface (3.38 × 10⁻⁹ vs 1.65 × 10⁻⁹ m²K/W).
• Heating induced a stable amorphous layer at the reactive interface, increasing TBR.

Conclusions:

• Chemical activity at solid interfaces significantly increases thermal boundary resistance.
• The formation of an amorphous layer due to heating is responsible for the enhanced TBR.
• This study provides insights for designing multi-layered structures with tailored thermal properties.