Hoffmann, Jörg

[["dc.bibliographiccitation.artnumber","033011"],["dc.bibliographiccitation.journal","New Journal of Physics"],["dc.bibliographiccitation.volume","17"],["dc.contributor.author","Scherff, Malte"],["dc.contributor.author","Meyer, B."],["dc.contributor.author","Hoffmann, J."],["dc.contributor.author","Jooss, C."],["dc.contributor.author","Feuchter, Manuel"],["dc.contributor.author","Kamlah, Marc"],["dc.date.accessioned","2018-11-07T09:59:48Z"],["dc.date.available","2018-11-07T09:59:48Z"],["dc.date.issued","2015"],["dc.description.abstract","We report here on the presence of two different nonvolatile resistive switching mechanisms in Pt-Pr0.67Ca0.33MnO3-Pt sandwich structures based on pulsed electrical transport measurements. As a function of pulse length, amplitude and temperature, the devices show two different switching regimes. The first is positive switching (PS) where a high resistance state (HRS) evolves at positive bias at the top electrode in the voltage range of U approximate to 0.5-1.2 V and pulse lengths t(p) approximate to 10(-7) s. In addition, we observe a cross over to negative switching (NS) for U > 1 V and t(p) approximate to 10(-3) s. Here, the HRS evolves at negative bias applied at the top electrode. We present strong evidence that both switching mechanisms take place at the interface between Pr0.67Ca0.33MnO3 and the top electrode. Based on finite element simulations of the temperature evolution during the electrical pulses, we show that the onset of Joule heating is characteristic of the PS regime, whereas drastic temperature increases of several hundred Kelvin evolve during NS. Based on the observed different timescales, pulse amplitudes and temperature dependences of PS and NS, respectively, we suggest that two different switching mechanisms are involved: a fast, short range exchange of oxygen at the interface with the metallic electrode for PS and a slower, long range redistribution of oxygen in the entire PCMO film for the NS."],["dc.description.sponsorship","Open Access Publikationsfonds 2015"],["dc.identifier.doi","10.1088/1367-2630/17/3/033011"],["dc.identifier.isi","000352898500011"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/11865"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/37669"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Iop Publishing Ltd"],["dc.relation.issn","1367-2630"],["dc.relation.orgunit","Fakultät für Physik"],["dc.rights","CC BY 3.0"],["dc.title","Pulse length and amplitude dependent resistive switching mechanisms in Pt-Pr0.67Ca0.33MnO3-Pt sandwich structures"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","063046"],["dc.bibliographiccitation.journal","New Journal of Physics"],["dc.bibliographiccitation.volume","19"],["dc.contributor.author","Ifland, Benedikt"],["dc.contributor.author","Hoffmann, Joerg"],["dc.contributor.author","Kressdorf, Birte"],["dc.contributor.author","Roddatis, Vladimir"],["dc.contributor.author","Seibt, Michael"],["dc.contributor.author","Jooss, Christian"],["dc.date.accessioned","2018-11-07T10:22:28Z"],["dc.date.available","2018-11-07T10:22:28Z"],["dc.date.issued","2017"],["dc.description.abstract","The effect of correlation effects on photovoltaic energy conversion at manganite/titanite heterojunctions is investigated. As a model system we choose a heterostructure consisting of the small polaron absorber Pr0.66Ca0.34MnO3 (PCMO) epitaxially grown on single-crystalline Nb-doped SrTi0.998Nb0.002O3 (STNO) substrates. The high structural and chemical quality of the interfaces is proved by detailed characterization using high-resolution transmission electron microscopy (TEM) and electron energy loss spectroscopy (EELS) studies. Spectrally resolved and temperature-dependent photovoltaic measurements show pronounced contributions of both the Jahn-Teller (JT) excitations and the charge transfer (CT) transitions to the photovoltaic effect at different photon energies. A linear temperature dependence of the open-circuit voltage for an excitation in the PCMO manganite is only observed below the charge-ordering temperature, indicating that the diffusion length of the photocarrier exceeds the size of the space charge region. The photovoltaic response is compared to that of a heterojunction of lightly doped Pr0.05Ca0.95MnO3 (CMO)/STNO, where the JT transition is absent. Here, significant contributions of the CT transition to the photovoltaic effect set in below the Neel temperature. We conclude that polaronic correlations and ordering effects are essentials for photovoltaic energy conversion in manganites."],["dc.description.sponsorship","Deutsche Forschungsgemeinschaft (DFG) [SFB1073]"],["dc.description.sponsorship","Open-Access-Publikationsfonds 2017"],["dc.identifier.doi","10.1088/1367-2630/aa6c22"],["dc.identifier.isi","000404761900009"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/14592"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/42283"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","PUB_WoS_Import"],["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","1367-2630"],["dc.relation.orgunit","Fakultät für Physik"],["dc.relation.orgunit","Institut für Materialphysik"],["dc.rights","CC BY 4.0"],["dc.title","Contribution of Jahn-Teller and charge transfer excitations to the photovoltaic effect of manganite/titanite heterojunctions"],["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","2002049"],["dc.bibliographiccitation.issue","7"],["dc.bibliographiccitation.journal","Advanced Materials Interfaces"],["dc.bibliographiccitation.volume","8"],["dc.contributor.author","Hoffmann-Urlaub, Sarah"],["dc.contributor.author","Ross, Ulrich"],["dc.contributor.author","Hoffmann, Jörg"],["dc.contributor.author","Belenchuk, Alexandr"],["dc.contributor.author","Shapoval, Oleg"],["dc.contributor.author","Roddatis, Vladimir"],["dc.contributor.author","Ma, Qian"],["dc.contributor.author","Kressdorf, Birte"],["dc.contributor.author","Moshnyaga, Vasily"],["dc.contributor.author","Jooss, Christian"],["dc.date.accessioned","2021-04-14T08:29:32Z"],["dc.date.available","2021-04-14T08:29:32Z"],["dc.date.issued","2021"],["dc.description.abstract","Abstract Interest in layered Ruddlesden–Popper (RP) strongly correlated manganites of Pr0.5Ca1.5MnO4 as well as in their thin film polymorphs is motivated by the high temperature of charge orbital ordering above room temperature. The c‐axis orientation in epitaxial films is tailored by different SrTiO3 (STO) substrate orientations and CaMnO3 (CMO) buffer layers. Films on STO(110) show in‐plane alignment of the c‐axis parallel to the [100] direction. On STO(100), two possible directions of the in‐plane c‐axis lead to a mosaic like, quasi 2D nanostructure, consisting of RP, rock‐salt, and perovskite blocks. With the CMO buffer layer, Pr0.5Ca1.5MnO4 epitaxial films with c‐axis out‐of‐plane are realized. Different physical vapor deposition techniques as ion beam sputtering, pulsed laser deposition and metalorganic aerosol deposition are applied in order to distinguish effects of growth conditions from intrinsic epitaxial properties. Despite their very different growth conditions, surface morphology, crystal structure, and orientation of the thin films reveal a high level of similarity as verified by X‐ray diffraction, scanning, and high resolution transmission electron microscopy. For different epitaxial relations stress in the films is relaxed by means of modified interface chemistry. The charge ordering in the films occurs at a temperature close to that expected in bulk material."],["dc.description.abstract","The growth direction of a Ruddlesden–Popper Pr0.5Ca1.5MnO4 thin film is governed by its strain state. For different SrTiO3 substrate orientations the unit cells of the film are aligned in parallel or in a perpendicular configuration—forming a mosaic like microstructure. With a CaMnO3 buffer layer the c‐axis can even be tilted to the out‐of‐plane direction. image"],["dc.description.sponsorship","Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659"],["dc.identifier.doi","10.1002/admi.202002049"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/82926"],["dc.language.iso","en"],["dc.notes.intern","DOI Import GROB-399"],["dc.relation","SFB 1073: Kontrolle von Energiewandlung auf atomaren Skalen"],["dc.relation","SFB 1073 | Topical Area A | A02 Verständnis und Manipulation von Dissipationskanälen des Energietransports"],["dc.relation","SFB 1073 | Topical Area B | B02 Photonen-getriebener Energietransfer über Grenzflächen zwischen Materialien mit starken Korrelationen"],["dc.relation","SFB 1073 | Topical Area Z | Z02 Hochauflösende Charakterisierung von Grenzflächen"],["dc.relation.eissn","2196-7350"],["dc.relation.issn","2196-7350"],["dc.relation.orgunit","Institut für Materialphysik"],["dc.rights","This is an open access article under the terms of the Creative Commons Attribution‐NonCommercial‐NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non‐commercial and no modifications or adaptations are made."],["dc.title","Tailoring c-axis orientation in epitaxial Ruddlesden-Popper Pr0.5Ca1.5MnO4 films"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.subtype","original_ja"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","103008"],["dc.bibliographiccitation.issue","10"],["dc.bibliographiccitation.journal","New Journal of Physics"],["dc.bibliographiccitation.volume","15"],["dc.contributor.affiliation","Scherff, M;"],["dc.contributor.affiliation","Hoffmann, J;"],["dc.contributor.affiliation","Meyer, B;"],["dc.contributor.affiliation","Danz, Th;"],["dc.contributor.affiliation","Jooss, Ch;"],["dc.contributor.author","Scherff, Malte"],["dc.contributor.author","Hoffmann, J."],["dc.contributor.author","Danz, T. H."],["dc.contributor.author","Jooss, C. H."],["dc.contributor.author","Meyer, B"],["dc.date.accessioned","2018-11-07T09:18:43Z"],["dc.date.available","2018-11-07T09:18:43Z"],["dc.date.issued","2013"],["dc.date.updated","2022-02-10T07:03:55Z"],["dc.description.abstract","The identification of the cross-plane electric transport mechanisms in different resistance states of metal-oxide sandwich structures is essential for gaining insights into the mechanisms of resistive switching (RS). Here, we present a systematic study of cross-plane electric transport properties of Pr0.67Ca0.33MnO3 (PCMO) thin films sandwiched by precious Pt metal electrodes. We observe three different transport regimes: ohmic, nonlinear and RS. The nonlinear regime is associated with colossal magneto-resistance (CMR) and colossal electro-resistance (CER) effects. In contrast to RS, the CMR and CER are volatile resistance effects which persist only during application of strong magnetic or electric fields and they are restricted to low temperatures. At low current densities, the device resistance is dominated by small polaron hopping transport of the PCMO film. At higher electric current densities near the switching threshold, the interface resistance starts to dominate and remarkably also exhibits thermally activated transport properties. Our studies also shed light onto the interplay of colossal resistance effects and RS: at low temperatures, RS can be only induced by reduction of the PCMO resistivity through CMR and CER. This clearly demonstrates the key role of the current density for controlling the amplitude of non-volatile resistive changes. Conversely, the CMR can be used as a probe for the switching induced changes in disorder and correlations. At small switching amplitudes, we observe slight changes in polaron activation energy which can be attributed to changes at the interface. If the switching amplitude exceeds 1000% and more, the CMR effect in the device can be reversibly changed. This indicates persistent changes in electronic or lattice structure of large regions within the PCMO film."],["dc.description.sponsorship","Open-Access-Publikationsfonds 2013"],["dc.description.sponsorship","DFG [JO 348/10-1]"],["dc.identifier.doi","10.1088/1367-2630/15/10/103008"],["dc.identifier.eissn","1367-2630"],["dc.identifier.isi","000325322400001"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/9560"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/28466"],["dc.language.iso","en"],["dc.notes.intern","Merged from goescholar"],["dc.notes.oa","gold"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","IOP Publishing"],["dc.relation.issn","1367-2630"],["dc.relation.orgunit","Fakultät für Physik"],["dc.rights","CC BY 3.0"],["dc.rights.uri","http://creativecommons.org/licenses/by/3.0"],["dc.title","Interplay of cross-plane polaronic transport and resistive switching in Pt-Pr0.67Ca0.33MnO3-Pt heterostructures"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","129"],["dc.bibliographiccitation.issue","2"],["dc.bibliographiccitation.journal","Catalysts"],["dc.bibliographiccitation.lastpage","145"],["dc.bibliographiccitation.volume","4"],["dc.contributor.author","Mierwaldt, Daniel"],["dc.contributor.author","Mildner, Stephanie"],["dc.contributor.author","Arrigo, Rosa"],["dc.contributor.author","Knop-Gericke, Axel"],["dc.contributor.author","Franke, Emanuel"],["dc.contributor.author","Blumenstein, Andreas"],["dc.contributor.author","Hoffmann, Joerg"],["dc.contributor.author","Jooß, Christian"],["dc.date.accessioned","2018-11-07T09:39:09Z"],["dc.date.available","2018-11-07T09:39:09Z"],["dc.date.issued","2014"],["dc.description.abstract","Studying catalysts in situ is of high interest for understanding their surface structure and electronic states in operation. Herein, we present a study of epitaxial manganite perovskite thin films (Pr1-xCaxMnO3) active for the oxygen evolution reaction (OER) from electro-catalytic water splitting. X-ray absorption near-edge spectroscopy (XANES) at the Mn L- and O K-edges, as well as X-ray photoemission spectroscopy (XPS) of the O 1s and Ca 2p states have been performed in ultra-high vacuum and in water vapor under positive applied bias at room temperature. It is shown that under the oxidizing conditions of the OER a reduced Mn2+ species is generated at the catalyst surface. The Mn valence shift is accompanied by the formation of surface oxygen vacancies. Annealing of the catalysts in O-2 atmosphere at 120 degrees C restores the virgin surfaces."],["dc.description.sponsorship","DFG CRC 1073 project C02"],["dc.description.sponsorship","Deutsche Forschungsgemeinschaft through the CRC 1073 [C02]"],["dc.identifier.doi","10.3390/catal4020129"],["dc.identifier.isi","000339590600004"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/10510"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/33215"],["dc.notes","Financial support by the Deutsche Forschungsgemeinschaft through the CRC 1073 project C02"],["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 C | C02 In situ hochauflösende Untersuchung des aktiven Zustands bei der photo- und elektrochemischen Wasserspaltung"],["dc.relation.issn","2073-4344"],["dc.relation.orgunit","Fakultät für Physik"],["dc.relation.orgunit","Institut für Materialphysik"],["dc.title","In Situ XANES/XPS Investigation of Doped Manganese Perovskite Catalysts"],["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.issue","5"],["dc.bibliographiccitation.journal","Physical Review Applied"],["dc.bibliographiccitation.volume","14"],["dc.contributor.author","Kressdorf, B."],["dc.contributor.author","Meyer, T."],["dc.contributor.author","Belenchuk, A."],["dc.contributor.author","Shapoval, O."],["dc.contributor.author","ten Brink, M."],["dc.contributor.author","Melles, S."],["dc.contributor.author","Ross, U."],["dc.contributor.author","Hoffmann, J."],["dc.contributor.author","Moshnyaga, Vasily"],["dc.contributor.author","Seibt, Michael"],["dc.contributor.author","Blöchl, Peter"],["dc.contributor.author","Jooss, Christian"],["dc.date.accessioned","2021-04-14T08:31:35Z"],["dc.date.available","2021-04-14T08:31:35Z"],["dc.date.issued","2020"],["dc.description.abstract","Harvesting of solar energy by hot carriers from optically induced intraband transitions offers new perspectives for photovoltaic energy conversion. Clearly, mechanisms slowing down hot-carrier thermalization constitute a fundamental core of such pathways of third-generation photovoltaics. The intriguing concept of hot polarons stabilized by long-range phonon correlations in charge-ordered strongly correlated three-dimensional metal-oxide perovskite films has emerged and been demonstrated for Pr0.7Ca0.3MnO3 at low temperature. In this work, a tailored approach to extending such processes to room temperature is presented. It consists of a specially designed epitaxial growth of two-dimensional Ruddlesden-Popper Pr0.5Ca1.5MnO4 films on Nb:SrTiO3 with a charge-ordering transition at TCO ∼ 320 K. This opens the route to a different phonon-bottleneck strategy of slowing down carrier relaxation by strong coupling of electrons to cooperative lattice modes."],["dc.identifier.doi","10.1103/PhysRevApplied.14.054006"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/83645"],["dc.language.iso","en"],["dc.notes.intern","DOI Import GROB-399"],["dc.relation","SFB 1073: Kontrolle von Energiewandlung auf atomaren Skalen"],["dc.relation","SFB 1073 | Topical Area A | A02 Verständnis und Manipulation von Dissipationskanälen des Energietransports"],["dc.relation","SFB 1073 | Topical Area B | B02 Photonen-getriebener Energietransfer über Grenzflächen zwischen Materialien mit starken Korrelationen"],["dc.relation","SFB 1073 | Topical Area B | B03 Relaxation, Thermalisierung, Transport und Kondensation in hochangeregten Festkörpern"],["dc.relation","SFB 1073 | Topical Area Z | Z02 Hochauflösende Charakterisierung von Grenzflächen"],["dc.relation.eissn","2331-7019"],["dc.relation.orgunit","Institut für Materialphysik"],["dc.rights","CC BY 4.0"],["dc.title","Room-Temperature Hot-Polaron Photovoltaics in the Charge-Ordered State of a Layered Perovskite Oxide Heterojunction"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.subtype","original_ja"],["dc.type.version","published_version"],["dspace.entity.type","Publication"],["local.message.claim","2022-01-20T08:58:36.159+0000|||rp114901|||submit_approve|||dc_contributor_author|||None"]]

[["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.artnumber","2100464"],["dc.bibliographiccitation.journal","Small methods"],["dc.contributor.author","Meyer, Tobias"],["dc.contributor.author","Kressdorf, Birte"],["dc.contributor.author","Roddatis, Vladimir V."],["dc.contributor.author","Hoffmann, Jörg"],["dc.contributor.author","Jooss, Christian"],["dc.contributor.author","Seibt, Michael"],["dc.date.accessioned","2021-09-01T06:42:46Z"],["dc.date.available","2021-09-01T06:42:46Z"],["dc.date.issued","2021"],["dc.description.abstract","The rich phase diagram of bulk Pr1−xCaxMnO3 resulting in a high tunability of physical properties gives rise to various studies related to fundamental research as well as prospective applications of the material. Importantly, as a consequence of strong correlation effects, electronic and lattice degrees of freedom are vigorously coupled. Hence, it is debatable whether such bulk phase diagrams can be transferred to inherently strained epitaxial thin films. In this paper, the structural orthorhombic to pseudo-cubic transition for x = 0.1 is studied in ion-beam sputtered thin films and differences to the respective bulk system are pointed out by employing in situ heating nano-beam electron diffraction to follow the temperature dependence of lattice constants. In addition, it is demonstrated that controlling the environment during heating, that is, preventing oxygen loss, is crucial in order to avoid irreversible structural changes, which is expected to be a general problem of compounds containing volatile elements under non-equilibrium conditions."],["dc.identifier.doi","10.1002/smtd.202100464"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/89140"],["dc.language.iso","en"],["dc.notes.intern","DOI-Import GROB-455"],["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","SFB 1073 | Topical Area Z | Z02 Hochauflösende Charakterisierung von Grenzflächen"],["dc.relation.eissn","2366-9608"],["dc.relation.issn","2366-9608"],["dc.relation.orgunit","Institut für Materialphysik"],["dc.rights","CC BY-NC-ND 4.0"],["dc.title","Phase Transitions in a Perovskite Thin Film Studied by Environmental In Situ Heating Nano‐Beam Electron Diffraction"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.subtype","original_ja"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","9852"],["dc.bibliographiccitation.issue","16"],["dc.bibliographiccitation.journal","Nanoscale"],["dc.bibliographiccitation.lastpage","9862"],["dc.bibliographiccitation.volume","6"],["dc.contributor.author","Norpoth, Jonas"],["dc.contributor.author","Mildner, Stephanie"],["dc.contributor.author","Scherff, Malte"],["dc.contributor.author","Hoffmann, Joerg"],["dc.contributor.author","Jooß, Christian"],["dc.date.accessioned","2018-11-07T09:36:30Z"],["dc.date.available","2018-11-07T09:36:30Z"],["dc.date.issued","2014"],["dc.description.abstract","The mechanism of the electric-pulse induced resistance change effect in Au/Pr0.65Ca0.35MnO3/SrTi0.99Nb0.01O3 thin-film samples is studied by means of in situ electrical stimulation inside a transmission electron microscope. A detailed equivalent-circuit model analysis of the measured current voltage characteristics provides crucial information for the proper interpretation of the microscopy results. The electrical transport data of the electron-transparent samples used for the in situ investigations is verified by comparison to measurements of unpatterned thin-film samples. We find comprehensive evidence for electrochemical oxygen vacancy migration affecting the potential barrier of the pn junction between Pr0.65Ca0.35MnO3 and SrTi0.99Nb0.01O3 as well as the resistance of the manganite bulk. The high-resistance state formation in the Pr0.65Ca0.35MnO3 bulk is frequently accompanied by structural transformations, namely detwinning and superstructure formation, most likely as the result of the joint impact of dynamic charge inhomogenities by oxygen vacancy migration and injection of high carrier densities at the electrodes."],["dc.description.sponsorship","Deutsche Forschungsgemeinschaft (DFG) [JO 348/10-1, SFB1073]"],["dc.identifier.doi","10.1039/c4nr02020k"],["dc.identifier.isi","000340217900064"],["dc.identifier.pmid","25029190"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/11087"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/32631"],["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","2040-3372"],["dc.relation.issn","2040-3364"],["dc.relation.orgunit","Fakultät für Physik"],["dc.relation.orgunit","Institut für Materialphysik"],["dc.rights","CC BY 3.0"],["dc.title","In situ TEM analysis of resistive switching in manganite based thin-film heterostructures"],["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.artnumber","046403"],["dc.bibliographiccitation.issue","4"],["dc.bibliographiccitation.journal","Materials Research Express"],["dc.bibliographiccitation.volume","1"],["dc.contributor.author","Hoffmann, J."],["dc.contributor.author","Moschkau, P."],["dc.contributor.author","Mildner, Stephanie"],["dc.contributor.author","Norpoth, J."],["dc.contributor.author","Jooss, C."],["dc.contributor.author","Wu, L."],["dc.contributor.author","Zhu, Y."],["dc.date.accessioned","2018-11-07T09:32:22Z"],["dc.date.available","2018-11-07T09:32:22Z"],["dc.date.issued","2014"],["dc.description.abstract","The colossal magnetoresistance effect (CMR), the drop of the electric resistance by orders of magnitude in a strong magnetic field, is a fascinating property of strongly correlated electrons in doped manganites. Here, we present a detailed analysis of the magnetotransport properties of small polarons in thin films of the low bandwidth manganite Pr0.68Ca0.32MnO3 with different degrees of preparation- induced octahedral disorder. The crystal and defect structure is investigated by means of high-resolution transmission electron microscopy. We apply the small polaron theory developed by Firsov and Lang in order to study the hopping mobility in the paramagnetic phase and its changes due to the formation of the antiferromagnetic charge ordered (CO) and the ferromagnetic metallic phases. Although it represents a single particle theory, reasonable estimates of small polaron properties such as formation energy, activation energy and transfer integral are possible, if the effects of interactions and disorder are taken into account. Beyond the well-known effect of the magnetic double exchange on the transfer integral, we show that the emergence of band transport of small polarons in the CMR transition sensibly depends on the degree of octahedral disorder, the polaron-polaron interactions and the resulting long range order leading to a structural phase transition in the CO phase."],["dc.identifier.doi","10.1088/2053-1591/1/4/046403"],["dc.identifier.isi","000209665400124"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/11412"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/31744"],["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 C | C01 Hydrid-Anordnungen für die Untersuchung photo-induzierter mehrstufiger katalytischer Prozesse"],["dc.relation.issn","2053-1591"],["dc.relation.orgunit","Fakultät für Physik"],["dc.relation.orgunit","Institut für Materialphysik"],["dc.rights","CC BY 3.0"],["dc.title","Effects of interaction and disorder on polarons in colossal resistance manganite Pr0.68Ca0.32MnO3 thin 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"]]