Understanding Material Synthesis Conditions and Complexity at High-Pressure

Introduction

Functional materials with outstanding technological properties can be found under extreme pressures and temperatures. This is particularly true for nitrides and hydrides, where the application of high-pressure high-temperature (HPHT) conditions has recently revealed an unexpectedly rich and complex chemistry.

Properties and Applications

These conditions have enabled the synthesis of compounds showing outstanding mechanical and electronic properties with applications in:

• Electronics
• Hard coatings
• Hydrogen storage
• Superconductivity
• Many more

Challenges

However, great challenges remain to be conquered in order to truly explore the possibilities permitted by these exotic materials. Indeed, their properties often vanish when brought back to ambient conditions, either because:

1. The atomic arrangement becomes energetically unfavourable.
2. The underlying physical processes become energetically unfavourable.

Moreover, the importance of finite-T effects and the structural and dynamical complexity of these HPHT phases prohibit computations from efficiently guiding experimental synthesis.

Project Goal

The goal of this project is to provide the computational tools for guiding the efficient and targeted synthesis of next-generation technological materials, including:

• The choice of synthesis conditions
• The selection of precursor materials

We will search for materials that retain their functional properties under decompression or are directly synthesizable at ambient pressure.

Methodology

To accomplish this, we will develop a workflow based on machine learning inter-atomic potentials to numerically explore experimental synthesis conditions at ab-initio accuracy. This will enable:

• An analysis of thermodynamic competition between different phases at HPHT
• Rigorous benchmarking against experiments to ensure that we truly portray nature's behaviour

Conclusion

This project will open up uncharted horizons for exploiting pressure and temperature as thermodynamic variables to explore new chemistry and synthesis pathways, ultimately guiding experiments towards industrially relevant novel technological materials.