% IMPORTANT: The following is UTF-8 encoded. This means that in the presence
% of non-ASCII characters, it will not work with BibTeX 0.99 or older.
% Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or
% “biber”.
@PHDTHESIS{Usler:1013964,
author = {Usler, Adrian Leonhard},
othercontributors = {De Souza, Roger Armand and Lüchow, Arne},
title = {{I}nvestigation of charge and mass transport in
ion-conducting solids by means of continuum and atomistic
simulations},
school = {RWTH Aachen University},
type = {Dissertation},
address = {Aachen},
publisher = {RWTH Aachen University},
reportid = {RWTH-2025-05829},
pages = {1 Online-Ressource : Illustrationen},
year = {2025},
note = {Veröffentlicht auf dem Publikationsserver der RWTH Aachen
University; Dissertation, RWTH Aachen University, 2025},
abstract = {A rational design of electroceramics requires a detailed
understanding of defect transport, both within the bulk of
the crystalline grains and across the grain boundaries.
These two overarching topics are approached in this work
from a computational perspective. The first part of this
work is dedicated to the common practice of predicting
ion-transport properties by extracting a diffusion
coefficient from Molecular Dynamcis simulations. This
practice is subjected to methodological scrutiny with regard
to the statistical error in the simulation outcome. The
dependence of the statistical error on simulation parameters
is analysed by means of kinetic Monte Carlo (kMC)
simulations. On the basis of the results, a mathematical
expression is introduced that allows for a simple assessment
of the statistical error from a single simulation. In the
following parts of this work, space-charge phenomena at
grain boundaries in solid electrolytes are studied by means
of continuum simulations. In the second part, grain-boundary
impedance is calculated from drift–diffusion simulations
of different space-charge models. Frozen-in profiles of
accumulated acceptor cations at the grain boundaries are
modelled in the scope of the restricted-equilibrium model.
It is analysed how this feature translates into systematic
errors in the determination of the space-charge potential
from impedance data. In the third part, space-charge layers
are approached from a combined atomistic and continuum
perspective. First, segregation energies of oxygen vacancies
and acceptor cations are obtained from Molecular Statics
simulations on a model grain boundary. It is then studied on
the continuum level how the variety of segregation energies
affects the temperature dependence of the space-charge
potential, and to which degree space-charge models may be
simplified. In the fourth part, grain-boundary impedance is
obtained from drift–diffusion simulations of space-charge
layers in a concentrated solid solution. The influence of
defect–defect simulations on the configuration of the
space-charge layers is modelled in the scope of the
Poisson–Cahn model. Lastly, in the fifth part, the effects
of a transition between different bulk defect-chemical
regimes on the temperature dependence of the space-charge
potential are analysed, and it is discussed how the
differences between these regimes lead to disparities
between experimental data gathered in different temperature
ranges.},
cin = {153110 / 150000},
ddc = {540},
cid = {$I:(DE-82)153110_20140620$ / $I:(DE-82)150000_20140620$},
pnm = {DFG project G:(GEPRIS)274005202 - SPP 1959: Manipulation of
matter controlled by electric and magnetic fields: Towards
novel synthesis and processing routes of inorganic materials
(274005202)},
pid = {G:(GEPRIS)274005202},
typ = {PUB:(DE-HGF)11},
doi = {10.18154/RWTH-2025-05829},
url = {https://publications.rwth-aachen.de/record/1013964},
}
guest ::