Kramer, Thilo

[["dc.bibliographiccitation.artnumber","243502"],["dc.bibliographiccitation.issue","24"],["dc.bibliographiccitation.journal","Applied Physics Letters"],["dc.bibliographiccitation.volume","110"],["dc.contributor.author","Kramer, Thilo"],["dc.contributor.author","Scherff, Malte"],["dc.contributor.author","Mierwaldt, Daniel"],["dc.contributor.author","Hoffmann, Joerg"],["dc.contributor.author","Jooss, Christian"],["dc.date.accessioned","2018-11-07T10:22:44Z"],["dc.date.available","2018-11-07T10:22:44Z"],["dc.date.issued","2017"],["dc.description.abstract","Non-volatile resistance change under electric stimulation in oxides is a promising path to next generation memory devices. However, the underlying mechanisms are still not fully understood. We report here on the study of switching in Pr0.67Ca0.33MnO3-delta (PCMO) films sandwiched by noble metal Pt electrodes, where electrode oxidation can be excluded. In order to develop an understanding of the switching induced oxygen migration, its initial concentration is modified by post-annealing of the deposited PCMO films. The oxygen distribution is obtained by manganese valence determination using spatially resolved electron energy loss spectroscopy in scanning transmission electron microscopy mode. We observe correlations between virgin state resistance, resistive switching properties, oxygen vacancy distribution, and stress/strain state of the PCMO films and propose a simplified interface resistance model based on the measured valence distribution. It assumes a linear correlation of oxygen vacancy concentration with conductivity and a metal to insulator transition above a critical vacancy concentration threshold. Our results suggest that resistance changes can take place at both interfaces of symmetric devices and only requires small changes in oxygen vacancy concentration. (C) 2017 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/)."],["dc.description.sponsorship","DFG [Jo 348/10-01]"],["dc.identifier.doi","10.1063/1.4985645"],["dc.identifier.isi","000403678300029"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/42329"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","PUB_WoS_Import"],["dc.relation.issn","1077-3118"],["dc.relation.issn","0003-6951"],["dc.relation.orgunit","Institut für Materialphysik"],["dc.title","Role of oxygen vacancies for resistive switching in noble metal sandwiched Pr0.67Ca0.33MnO3-delta"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original_ja"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1462"],["dc.bibliographiccitation.issue","11"],["dc.bibliographiccitation.journal","Journal of Materials Research"],["dc.bibliographiccitation.lastpage","1470"],["dc.bibliographiccitation.volume","27"],["dc.contributor.author","Hoffmann, Joerg"],["dc.contributor.author","Schnittger, Sven"],["dc.contributor.author","Norpoth, Jonas"],["dc.contributor.author","Raabe, Stephanie"],["dc.contributor.author","Kramer, Thilo"],["dc.contributor.author","Jooss, Christian"],["dc.date.accessioned","2018-11-07T09:10:03Z"],["dc.date.available","2018-11-07T09:10:03Z"],["dc.date.issued","2012"],["dc.description.abstract","Fabrication of thin film nanocomposites via decomposition and self-assembly from the vapor phase is a promising path for cost-effective fabrication of multifunctional materials. In particular, oxides as a new class of energy materials allow for rich functionalities, e. g., by combining p-and n-doped systems in catalytic or light harvesting units. Combining A-site doped perovskites ABO(3) with CoFe2O4 spinel, we have investigated thin film phase composition and nanocomposite morphology in the pseudobinary system La0.6Sr0.4BO3-CoFe2O4 for B = Fe, Co, and Mn. We observe formation of an epitaxial two-phase nanocomposite for B = Fe, i.e., the coexistence of La0.6Sr0.4FeO3 and CoFe2O4. In contrast, for B = Co or Mn nanocomposites are formed, where perovskite La0.6Sr0.4BO3 solid solutions coexists with Co-rich spinel and periclase phases. We derive conclusions for the preparation of perovskite-spinel nanocomposites with well-designed doping levels."],["dc.description.sponsorship","Deutsche Forschungsgemeinschaft [JO 348/8, SFB 602]"],["dc.identifier.doi","10.1557/jmr.2012.84"],["dc.identifier.isi","000304067600006"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/26404"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Cambridge Univ Press"],["dc.relation.issn","0884-2914"],["dc.title","Nanocomposite stability in Fe-, Co-, and Mn-based perovskite/spinel systems"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","3758"],["dc.bibliographiccitation.issue","19"],["dc.bibliographiccitation.journal","Chemistry of Materials"],["dc.bibliographiccitation.lastpage","3764"],["dc.bibliographiccitation.volume","24"],["dc.contributor.author","Sadhu, Anustup"],["dc.contributor.author","Kramer, Thilo"],["dc.contributor.author","Datta, Abheek"],["dc.contributor.author","Wiedigen, Stefanie Anna"],["dc.contributor.author","Norpoth, Jonas"],["dc.contributor.author","Jooss, Christian"],["dc.contributor.author","Bhattacharyya, Sayan"],["dc.date.accessioned","2018-11-07T09:04:41Z"],["dc.date.available","2018-11-07T09:04:41Z"],["dc.date.issued","2012"],["dc.description.abstract","Although the magnetic phase diagrams of bulk and thin film samples of Pr1-xCaxMnO3 (x <= 0.5) are widely explored, few works have been published on the magnetic properties of nanoparticles, especially in the lightly, doped regime. In this paper, microwave irradiation was used to synthesize the Pr0.977Ca0.023MnO3 and Pr0.964Ca0.036MnO3 Manganite phases with Pnma space group in the form of anisotropic nanoparticles. The phase identification, structural characteristics, and formation of the nanostructures were analyzed by Rietveld analysis of the X-ray diffraction patterns, electron microscopy, and combining thermal analysis with infrared spectroscopy, respectively. Transport measurements on the annealed samples revealed the insulating nature, and electrical conduction occurs through thermally activated hopping of small polarons. The Mn-O-c-Mn tilt angles in the MnO6 octahedra show considerable flattening (160.9 degrees and 167.6 degrees for x = 0.023 and x = 0.036, respectively), possibly enhancing the electronic double exchange and promoting ferromagnetism. Ferromagnetic ordering of Mn spins was indeed observed below 109 K, and interestingly, the magnetic moment for x = 0.036 was 3.92 mu(B)/f.u. at 5 K, which is higher than the saturated Mn magnetic moment (3.8 mu(B)). The enhanced magnetization is attributed to ordering of the Pr spins."],["dc.description.sponsorship","University Grants Commission (UGC), New Delhi; IISER Kolkata"],["dc.identifier.doi","10.1021/cm3018924"],["dc.identifier.isi","000309505100012"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/25164"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Amer Chemical Soc"],["dc.relation.issn","0897-4756"],["dc.title","Ferromagnetism in Lightly Doped Pr1-xCaxMnO3 (x=0.023, 0.036) Nanoparticles Synthesized by Microwave Irradiation"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","515"],["dc.bibliographiccitation.journal","Acta Materialia"],["dc.bibliographiccitation.volume","122"],["dc.contributor.author","Wagner, Stefan"],["dc.contributor.author","Kramer, Thilo"],["dc.contributor.author","Uchida, Helmut"],["dc.contributor.author","Dobron, Patrik"],["dc.contributor.author","Cizek, Jakub"],["dc.contributor.author","Pundt, Astrid"],["dc.date.accessioned","2022-01-25T09:58:14Z"],["dc.date.available","2022-01-25T09:58:14Z"],["dc.date.issued","2017"],["dc.identifier.doi","10.1016/j.actamat.2016.10.001"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/98625"],["dc.identifier.url","https://publications.goettingen-research-online.de/handle/2/43670"],["dc.relation.iserratumof","/handle/2/40034"],["dc.relation.issn","1359-6454"],["dc.relation.orgunit","Institut für Materialphysik"],["dc.title","Corrigendum to “Mechanical stress and stress release channels in 10–350 nm palladium hydrogen thin films with different micro-structures” [Acta Mater. 114 (2016) 116–125]"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.subtype","original_ja"],["dc.type.subtype","erratum_ja"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","9762"],["dc.bibliographiccitation.issue","15"],["dc.bibliographiccitation.journal","Physical Chemistry Chemical Physics"],["dc.bibliographiccitation.lastpage","9769"],["dc.bibliographiccitation.volume","19"],["dc.contributor.author","Martin, Johannes"],["dc.contributor.author","Graef, Melanie"],["dc.contributor.author","Kramer, Thilo"],["dc.contributor.author","Jooss, Christian"],["dc.contributor.author","Choe, Min-Ju"],["dc.contributor.author","Thornton, Katsuyo"],["dc.contributor.author","Weitzel, Karl-Michael"],["dc.date.accessioned","2018-11-07T10:24:53Z"],["dc.date.available","2018-11-07T10:24:53Z"],["dc.date.issued","2017"],["dc.description.abstract","The transport of potassium through praseodymium-manganese oxide (PrMnO3; PMO) has been investigated by means of the charge attachment induced transport (CAIT) technique. To this end, potassium ions have been attached to the front side of a 250 nm thick sample of PMO. The majority of the potassium ions become neutralized at the surface of the PMO, while some of the potassium ions diffuse through. Ex situ analysis of the sample by time-of-flight secondary ion mass spectrometry (ToF-SIMS) reveals pronounced concentration profiles of the potassium, which is indicative of diffusion. Two diffusion coefficients have been obtained, namely, the bulk diffusion coefficient and the diffusion coefficient associated with the grain boundaries. The latter conclusion is supported by transmission electron microscopy of thin lamella cut out from the sample, which reveals twin grain boundaries reaching throughout the entire sample as well as model calculations."],["dc.identifier.doi","10.1039/c7cp00198c"],["dc.identifier.isi","000399383100008"],["dc.identifier.pmid","28265624"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/42742"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","PUB_WoS_Import"],["dc.relation.issn","1463-9084"],["dc.relation.issn","1463-9076"],["dc.relation.orgunit","Institut für Materialphysik"],["dc.title","Charge attachment induced transport - bulk and grain boundary diffusion of potassium in PrMnO3"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original_ja"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","61"],["dc.bibliographiccitation.journal","Ultramicroscopy"],["dc.bibliographiccitation.lastpage","70"],["dc.bibliographiccitation.volume","184"],["dc.contributor.author","Kramer, Thilo"],["dc.contributor.author","Mierwaldt, Daniel"],["dc.contributor.author","Scherff, Malte"],["dc.contributor.author","Kanbach, Mike"],["dc.contributor.author","Jooss, Christian"],["dc.date.accessioned","2020-12-10T15:21:40Z"],["dc.date.available","2020-12-10T15:21:40Z"],["dc.date.issued","2018"],["dc.identifier.doi","10.1016/j.ultramic.2017.08.012"],["dc.identifier.issn","0304-3991"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/73108"],["dc.language.iso","en"],["dc.notes.intern","DOI Import GROB-354"],["dc.relation.orgunit","Institut für Materialphysik"],["dc.title","Developing an in situ environmental TEM set up for investigations of resistive switching mechanisms in Pt-Pr1-xCaxMnO3-δ-Pt sandwich structures"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.subtype","original_ja"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","616"],["dc.bibliographiccitation.journal","Electrochimica Acta"],["dc.bibliographiccitation.lastpage","623"],["dc.bibliographiccitation.volume","191"],["dc.contributor.author","Martin, Johannes"],["dc.contributor.author","Mehrwald, Sarah"],["dc.contributor.author","Schaefer, Martin"],["dc.contributor.author","Kramer, Thilo"],["dc.contributor.author","Jooss, Christian"],["dc.contributor.author","Weitzel, Karl-Michael"],["dc.date.accessioned","2018-11-07T10:18:15Z"],["dc.date.available","2018-11-07T10:18:15Z"],["dc.date.issued","2016"],["dc.description.abstract","The competition of Na+ ion versus K+ ion transport in a mixed alkali borosilicate glass has been investigated by low energy bombardment induced ion transport employing Cs+ ions as the foreign ion. Electrodiffusion causes the replacement of Na+ and K+ down to about 200 nm below the surface of the glass. Beyond this electrodiffusion front (in the direction of ion transport) K+ ions accumulate to a density above the bulk concentration while Na+ is further depleted towards the backside electrode. At the backside electrode only Na is electrodeposited since the electrical potential does not allow for K electrodeposition. A full simulation of the electrodiffusion profiles reveals the complete concentration dependence of the diffusion coefficients of the Na+ and K+ ions. (C) 2016 Elsevier Ltd. All rights reserved."],["dc.description.sponsorship","Deutsche Forschungsgemeinschaft (DFG)"],["dc.identifier.doi","10.1016/j.electacta.2016.01.061"],["dc.identifier.isi","000371143200071"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/41400"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Pergamon-elsevier Science Ltd"],["dc.relation.issn","1873-3859"],["dc.relation.issn","0013-4686"],["dc.title","Transport of ions in a mixed Na+/K+ ion conducting glass - electrodiffusion profiles and electrochemical interphase formation"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","935167"],["dc.bibliographiccitation.journal","Journal of Nanomaterials"],["dc.contributor.author","Ifland, Benedikt"],["dc.contributor.author","Hoffmann, Joerg"],["dc.contributor.author","Kramer, Thilo"],["dc.contributor.author","Scherff, Malte"],["dc.contributor.author","Mildner, Stephanie"],["dc.contributor.author","Jooss, Christian"],["dc.date.accessioned","2018-11-07T10:02:49Z"],["dc.date.available","2018-11-07T10:02:49Z"],["dc.date.issued","2015"],["dc.description.abstract","The deposition of heteroepitaxial thin films on single crystalline substrates by means of physical deposition methods is commonly accompanied by mechanical strain due to lattice mismatch and defect generation. Here we present a detailed analysis of the influence of strain on the Mn solubility of Pr1-xCaXMnO3 thin films prepared by ion-beam sputtering. Combining results from X-ray diffraction, transmission electron microscopy and in situ hot-stage stress measurements, we give strong evidence that large tensile strain during deposition limits the Mn solubility range of the Perovskite phase to near-stoichiometric composition. Mn excess gives rise to MnO2. precipitates and the precipitation seems to represent a stress relaxation path. With respect to size and density of the precipitates, the relaxation process can be affected by the choice of substrate and the deposition parameters, that is, the deposition temperature and the used sputter gas."],["dc.description.sponsorship","DFG [SFB 1073]"],["dc.identifier.doi","10.1155/2015/935167"],["dc.identifier.isi","000363631200001"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/12547"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/38308"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.relation","SFB 1073: Kontrolle von Energiewandlung auf atomaren Skalen"],["dc.relation","SFB 1073 | Topical Area B | B02 Photonen-getriebener Energietransfer über Grenzflächen zwischen Materialien mit starken Korrelationen"],["dc.relation.issn","1687-4129"],["dc.relation.issn","1687-4110"],["dc.relation.orgunit","Fakultät für Physik"],["dc.relation.orgunit","Institut für Materialphysik"],["dc.rights","CC BY 3.0"],["dc.title","Strain Driven Phase Decomposition in Ion-Beam Sputtered Pr1-XCaXMnO3 Films"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original_ja"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","116"],["dc.bibliographiccitation.journal","Acta Materialia"],["dc.bibliographiccitation.lastpage","125"],["dc.bibliographiccitation.volume","114"],["dc.contributor.author","Wagner, Stefan"],["dc.contributor.author","Kramer, Thilo"],["dc.contributor.author","Uchida, Helmut"],["dc.contributor.author","Dobron, Patrik"],["dc.contributor.author","Cizek, Jakub"],["dc.contributor.author","Pundt, Astrid"],["dc.date.accessioned","2018-11-07T10:11:24Z"],["dc.date.available","2018-11-07T10:11:24Z"],["dc.date.issued","2016"],["dc.description.abstract","For thin metal films adhered to rigid substrates hydrogen uptake results in compressive stresses in the GPa range. Stresses affect the thermodynamics as well as the durability of thin films, but many films can release stress above critical stress values. Depending on the films' thickness, microstructure and adhesion to the substrate, which determine the energy available in the nano-sized system, stress release is conducted via different release mechanisms. To evaluate the different mechanisms, Palladium thin films ranging from 10 nm to 350 nm and with three different types of microstructures (nanocrystalline, multi oriented epitaxy and three-fold epitaxy) are studied with special focus on the mechanical stress. In-situ substrate curvature measurements, XRD stress analyses and acoustic emission (AE) measurements are conducted to determine intrinsic stresses, hydrogen-induced stress changes and stress release signals. By this complementary experimental approach, different stress release mechanisms (named channels) are identified. Discrete stress relaxation (DSR) events are found already within the overall linear elastic stress-strain regime. Energies to stimulate DSR5 lay well below the formation energy of dislocations, and may allow the movement of defects pre-existing in the films. For higher strain energies, all studied films can release stress by the formation of new dislocations and plastic deformation. When the adhesion to the substrate is small, an alternative release channel of film buckling opens for thick films. (C) 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved."],["dc.identifier.doi","10.1016/j.actamat.2016.05.023"],["dc.identifier.isi","000378962600012"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/40034"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.relation.haserratum","/handle/2/98625"],["dc.relation.issn","1873-2453"],["dc.relation.issn","1359-6454"],["dc.relation.orgunit","Institut für Materialphysik"],["dc.title","Mechanical stress and stress release channels in 10-350 nm palladium hydrogen thin films with different micro-structures"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original_ja"],["dspace.entity.type","Publication"]]