Berlin 2018 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

DS: Fachverband Dünne Schichten

DS 3: Oxide Semiconductors for Novel Devices (Focussed Session): Session I

DS 3.5: Talk

Monday, March 12, 2018, 10:30–10:45, E 020

Considerations in the Stability of Multicomponent Oxide Alloys — •Christopher Sutton¹, Robert J.N. Baldock², Luca M. Ghiringhelli¹, and Matthias Scheffler¹ — ¹Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin, Germany — ²Ecole Polytech- nique Federale de Lausanne, Lausanne, Switzerland

Identification of stable crystalline materials for a mixture of two (three) components requires examination of the lowest free energy of approx- imately 2^N (3^N ) configurations, where N is the number of atoms in the unit cell. Cluster expansion-based energy functions offer a numerically efficient approach for estimating the stability of new potential alloys. Combining this approach with the nested sampling algorithm, which is a Bayesian Markov chain Monte Carlo method, allows for a one-shot calculation of the phase diagram as a function of composition and temperature. Our results for stable ternary and quaternary mixtures in various crystalline symmetries of group-III oxides with the formula (In_xGa_yAl_z)₂O₃ where x+y+z=1 will be presented. The key aspects that determine the stability of these materials will be discussed. With an extensive search over configurational space, statistical learning is performed for the bandgaps and stabilities to identify structure-property relationships between the targeted properties (e.g., optical transparency) and the fundamental chemical and physical parameters that control these properties.