JG-GH-UCLouvain · A materials informatics approach to the Pauling’s rules and structure-property relationships in low thermal conductivity materials

A materials informatics approach to the Pauling’s rules and structure-property relationships in low thermal conductivity materials

Inorganic materials are essential to a large part of our modern life and are part of the solution for many of the major problems of modern society. For example, thermoelectric materials, by transforming heat to electricity, could potentially increase the energy efficiency of production sites, aircrafts or cars. The design and discovery of materials is strongly dependent on the understanding of structure-property relationships. While structure-property relationships have always been central to materials science, the advent of materials informatics offers new exciting opportunities to discover structure-property relationships. A very well established and powerful way to describe inorganic crystal structures is through coordination polyhedra. With the help of these coordination polyhedra, some crystals have been rationalized and predicted. Linus Pauling based his famous five rules on the stability of ionic crystals on these coordination polyhedra and their connections. These five rules can be seen as structure-property relationships with stability as the property. Within the project, we have statistically assessed these five Pauling rules for a set of 5000 oxides for the first time. We have seen that these rules are only of limited predictive power. The rules two to five only work for roughly 13% of all tested oxides. Unfortunately, these rules cannot be used for a fast evaluation of the stability of materials due to their limited predictive power. In addition to understanding materials based on their coordination environments, there are other possibilities. Another possibility is bonding analysis using the Crystal Orbital Hamilton Population, for which we have developed tools that automatize these calculations and allow for high-throughput calculations within in this project. This allowed us to test a new implementation into a well-known software package and to use this tool in several ab initio high-throughput studies to understand the results. One of these high-throughput studies identified new ferroelectric materials that could be used in low-power storage devices. Based on the detailed investigation of a thermoelectric material (14-1-11), we have developed a new design principle to arrive at materials with low thermal conductivity. Beyond chemical heuristics and design principles, machine-learned interatomic potentials also allow material properties to be calculated in an accelerated manner. As an alternative to heuristics, in this project we investigated how we can use these potentials for vibrational properties. A new recipe for constructing databases on which to base these potentials was developed in the process. We were thus able to calculate the phonon properties of several silicon allotropes in good agreement with ab initio calculations. We have also shown that thermal conductivities can be calculated based on this approach which might allow to discover thermoelectric materials with low thermal conductivities in the future. In the course of the project, we have seen that tools from materials informatics can indeed be very helpful to find and understand new materials for many applications (thermoelectric materials, ferroelectric materials) and that tools based on coordination environments and also bonding analysis can be used for this.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз