DFT Study on the Oxygen Migration in Manganite Compounds

HUNT, DIEGO; JUAN, DILSON; AKHTAR, ARSALAN; FERRARI, VALERIA

Partido de San Martín, Provincia de Buenos Aires

Conferencia; XIX Encuentro de superficies y materiales nanostructurados NANO2019; 2019

CNEA - INTI

Complex manganese oxides have been the subject of intense study for decades due to the discovery ofboth intrinsic and extrinsic properties such as colossal magnetoresistance, ferroelectricity, and metalinsulatortransitions, among others. This variety of properties promises several technological applicationsfor manganites. Recently, this material has been extensively used as cathode in solid oxide fuel cells(SOFCs), a clean energy generation technology which takes advantage of particular characteristicsregarding the chemical and structural stability, ionic-electronic conductivity and catalytic activity ofmanganites. In this work, we present a study about the diffusion of oxygen vacancies, focusing on the roleof Sr-doping in the formation energies and migration barriers for La(1-x)SrxMnO3 compounds by means ofthe Density Functional Theory (DFT) and the Nudged Elastic Band (NEB) method. We employ themodule implemented in QUANTUM ESPRESSO and the corresponding scheme of SIESTA, provided byan external loop controlling programming language (LUA), in order to compare and validate results andperformances. The distribution of Sr ions within the crystal structure is obtained using the randomdistribution of binary alloys, which allow us to explore Sr-rich and Sr-poor environments. We focus on arange of composition 0.20