A first-principles non-equilibrium molecular dynamicsstudy of oxygen diffusion in Sm-doped ceria
Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
Solid oxide fuel cells are considered as one of the main alternatives for future sources of clean energy. To further improve their performance, theoretical methods able to describe the diffusion process in candidate electrolyte materials at finite temperatures are needed. The method of choice for simulating systems at finite temperature is molecular dynamics. However, if the forces are calculated directly from the Schrödinger equation (first-principles molecular dynamics) the computational expense is too high to allow long enough simulations to properly capture the diffusion process in most materials.
This thesis introduces a method to deal with this problem using an external force field to speed up the diffusion process in the simulation. The method is applied to study the diffusion of oxygen ions in Sm-doped ceria, which has showed promise in its use as an electrolyte. Good agreement with experimental data is demonstrated, indicating high potential for future applications of the method.
Place, publisher, year, edition, pages
2015. , 68 p.
density functional theory, non-equilibrium molecular dynamics, color diffusion, Sm-doped ceria, CeO2, ionic conductivity, solid oxide fuel cells
Condensed Matter Physics
IdentifiersURN: urn:nbn:se:liu:diva-118773ISRN: LITH-IFM-A-EX--15/3093—SEOAI: oai:DiVA.org:liu-118773DiVA: diva2:816692
Subject / course
Vekilova, Olga, Dr.
Simak, Sergei, Professor