Dokumente Fakultät für Physik (inkl. GAUSS) nach Gutachter "Jooß, Christian Prof. Dr."
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Metal Impurity Redistribution in Crystalline Silicon for Photovoltaic Application
(2014-11-14)Multicrystalline silicon, which is among the most common materials for solar cells [3], contains extended defects like grain boundaries and dislocations and a high amount of metal impurities potentially reducing the solar ... -
Phase-Dependent Energy Dissipation Processes in La0.7Sr0.3MnO3 and (La0.6Pr0.4)0.7Ca0.3MnO3 after an Ultrashort Optical Excitation
(2023-08-31)La0.7Sr0.3MnO3 (LSMO) and (La0.6Pr0.4)0.7Ca0.3MnO3 (LPCMO) are perovsikte manganites which both show a ferromagnetic-to-paramagnetic phase transition. Interestingly, the development of the new phase when crossing the ... -
Photo-magnonics in two-dimensional antidot lattices
(2013-01-11)The essential subject of the present (cumulative) thesis is the all-optical generation and detection as well as the systematic manipulation of magnetic excitations, so-called spin waves or magnons. In particular, the ... -
Pr$_{1-x}$Ca$_x$MnO$_x$ for Catalytic Water Splitting - Optical Properties and In Situ ETEM Investigations
(2015-09-17)In this thesis, Ca-doped PrMnO$_3$ (PCMO) is evaluated as a catalyst for (photo)electrochemical water oxidation. The investigations are focused on elementary steps of the overall process. First, the optical absorption in ... -
Scanning Tunneling Spectroscopy of Subsurface Non-Magnetic Impurities in Copper
(2021-09-06)In this thesis, single non-magnetic Ge and Ag impurities buried in the bulk metal Cu are studied to characterize their scattering properties as well as the electronic structure of the host. This is possible by analyzing ... -
Spektrale Kontrolle von elastischer Dynamik und Wärmetransport in periodischen Nanostrukturen
(2021-11-26)In this dissertation I show theoretical and experimental investigations of phononic heat transport. In the first part of the thesis, I use femtosecond pump-probe spectroscopy to demonstrate how a wedge-shaped transducer ... -
Spindynamik in Tunnelelementen mit senkrechter magnetischer Anisotropie
(2015-02-11)During the last thirty years the memory space per square centimeter on the memory unit was increased exponential. The reason for such strong improvement is the continuous decreasing of the unit cells down to nanometer ... -
Structural and Electronic Investigation of Strongly Correlated Transition Metal Oxide Perovskite Thin Films and Interfaces using In-situ Transmission Electron Microscopy
(2021-09-09)Discussing the necessity as well as possible details of global strategies to reduce and eventually eliminate the anthropogenic climate change (ACC) is a delicate matter, which easily leads to statements based on ... -
Structure and photovoltaic properties of strongly correlated manganite/titanite heterojunctions
(2018-08-21)In the present thesis the photovoltaic (PV) effect in strongly correlated manganite/titanite heterostructures is investigated. As a model system thin films of Pr$_{1-x}$Ca$_{x}$MnO$_{3}$ (PCMO) were deposited on single ... -
The study of magnetic and polaronic microstructure in Pr1-xCaxMnO3 manganite series
(2018-09-21)Manganites have been studied intensively due to their extraordinary properties: colossal magnetoresistance and ferroelectricity. The inhomogeneities present in certain regions of the phase diagram are believed to be ... -
The tunnel magneto-Seebeck effect in magnetic tunnel junctions
(2014-01-30)The present (cumulative) thesis focusses on thermomagnetoelectric effects in magnetic tunnel junctions. In particular, it deals with the measurement of the tunnel magneto-Seebeck (TMS) effect in tunnel junctions incorporating ... -
Transmission electron microspy studies of ion migration in resistive switching platinum-manganite heterostructures
(2018-04-16)Non-volatile resistance change under electric stimulation in many metal-oxides is a promising path to next generation memory devices. However, the underlying mechanisms are still not fully understood. In this study ... -
Ultrafast transmission electron microscopy of a structural phase transition
(2021-08-09)High hopes are placed on materials with tunable properties and excitations for future applications in energy conversion devices. Functionality of devices, however, not only arises from the properties of individual materials ... -
Untersuchung der elektrischen Hyperfeinwechselwirkung in M<sub>n+1</sub>AX<sub>n</sub>-Phasen mittels der gestörten γ-γ-Winkelkorrelation
(2014-05-19)Mn+1AXn phases are thermodynamically stable nanolaminated ternary carbides and nitrides showing both metallic and ceramic properties. The letter M stands for an early transition metal, the letter A represents an A-element ... -
Untersuchung des elektrischen Widerstandsschaltens perowskitischer Manganatfilme auf der Nanometerskala
(2012-07-25)Perovskite manganese oxides are highly correlated systems, which exhibit a variety of resistance effects under different stimuli. Under exceeding critical voltages or currents, abrupt changes of the electrical resistance ... -
Wechselwirkungen von Gold und Versetzungen in Silizium
(2009-06-04)The knowledge about interactions of different defects in crystalline sillicon are of major importance for the optimisation of the performance of solar cells based on multicrystalline silicon. ... -
Zusammenspiel von Ladungs-, Gitter- und magnetischen Ordnungen in hochdotierten LCMO Schichten
(2015-07-27)This work is focused on the preparation and characterization of overdoped La_1-xCa_xMnO_3 films on MgO and as freestanding films. The charge ordering transition is being investigated via means of resistance, magnetization, ...