Dresden 2020 – wissenschaftliches Programm
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CPP 89.3: Vortrag
Donnerstag, 19. März 2020, 10:10–10:30, HSZ 301
First principles calculation on intrinsic defects properties of Sodium Niobate — •Lorenzo Villa — Fachgebiet Materialmodellierung, Institut für Materialwissenschaft, TU Darmstadt, Otto-Berndt-Straße 3, D-64287 Darmstadt, Germany
In recent years extended research has been focusing on improving the properties of capacitors for energy storage applications. In this context, lead-free antiferroelectric materials (AFE) are excellent candidates due to their ability of displaying high energy density, high energy efficiency and low environmental impact. In this class of compounds, NaNbO3 (NN) is amongst the most promising materials, due to the possibility to obtain double P-E loops at room temperature. One of the mostly used methods to obtain narrower antiferroelectric P-E loops is via doping. Intrinsic defects can interact with the dopants and therefore can have an impact on AFE properties. In order to investigate the interaction of intrinsic defects with dopants, we have studied the contribution of vacancies to intrinsic electron and hole conductivity and their interaction with different types of dopants (Sr, Ca, Mn). All calculations were performed in the framework of Density Functional Theory using Hybrid functionals. In particular, we have investigated the formation energies of all vacancy types considering all possible charge states in five different regions of the stability diagram.