Computational-based Research on (Geo)-Materials

Computational modelling of (geo)materials makes use of first-principles or ab initio calculations, that is, quantum mechanical computations based only on elemental physical constants of nature such as the electron charge, atomic masses, etc., with the main objective of understanding physical and chemical properties of a variety of materials studied because of their fundamental interest, their relevance in technological applications and their importance for Earth and planetary modelling.   Over the next 5-year period (2017-2022), the general goal of these investigations will be to increase our knowledge in the mineral physics, geophysics and materials science. In the geosciences, the understanding of Earth materials in terms of their atomic arrangements, structural bondings, chemical compositions, magnetic state, elastic coefficients, etc. will provide insights into the complex interactions between our surface environment and the deep planet. Moreover, the joint effort between the theoretical/computational modelling with the experimental part will advance a more accurate portrayal of our planet and others. Thus, our research will address the following questions:  

  • How does the elasticity of different iron-bearing olivine- and spinel-type minerals compare to 
each other as predicted by first-principles? 

  • How does cation disorder influence the physical properties of minerals belonging to the spinel, olivine and perovskite families? 

  • How does the electronic state of iron and other magnetic ions change in different minerals at high pressures –and what is the effect of such changes on the physical properties of the minerals? 

  • How are thermal and electrical conductivities altered by pressure, temperature, and composition? 
  

Figure 1: Examples of minerals currently under investigation. a) Lithiophilate-Triphylite [Li(Fe,Mn)PO4] crystal structures belong to the olivine-type family and the structural and magnetic properties of these materials at high-pressure are not well stablished yet. b) Spinels of the form MAl2O4 with M=Mg, Mn, are excellent candidates to study cation disorder (M⇔Al) and its effects on physical and chemical properties.

From the materials science point of view, the identification of precise features that controls the functionalities of complex materials for specific technological applications is the subject of intensive experimental, theoretical and computational research. In particular, within the area of “Georesources” using first-principles calculations, new functional materials and alternative energy sources can be designed and characterized, with the potential to become substitutes to natural resources in the long term.

Contact: Dr. Maribel Núñez-Valdez