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Showing 1 to 15 of 15 for “"Ruddlesden-Popper"”.
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New Ruddlesden-Popper Perovskites Obtained by Topochemical Methods
… materials were the single and triple layered Ruddlesden-Popper compounds, NaLnTiO4 (Ln = La and Gd) and A2La2Ti3O10 (A = Li and K). These compounds consist of [LnTiO4]- and [La2Ti3O10]2-, respectively, perovskite layers interleaved with two alkali metal ion strata. The topotactic routes used …
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Charge carrier transport and recombination in semiconductors: Insights from statistical analysis and machine learning techniques
… 4, efficient exciton energy transport in thin Ruddlesden-Popper perovskite flakes is visualised and understood using time-resolved photoluminescence microscopy. Excitons traverse through static disorder landscapes at low temperatures and diffusively hop between traps at higher temperatures, …
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Magneto-Optical Effects in Manganese-doped Lead Halide Perovskite
… dynamics. We synthesise manganese-doped 2D Ruddlesden-Popper perovskite phenethyl ammonium lead iodide thin films and characterise the material’s basic properties. We report qualitative evidence that, depending on doping concentrations, Mn2+ ions occupy different lattice sites, e.g., either …
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Novel Transition-Metal Oxides Under Pressure
… superconductivity is a more general property of Ruddlesden-Popper Ni-O stacks under pressure.
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The low-temperature formation of mixed-metal oxides
… lithium ion exchange of a series of protonated Ruddlesden-Popper layered perovskites (HLaTiO₄, H₂SrTa₂O₇ and H₂La₂Ti₃O₁₀), with a controlled proton and lithium content. This involves grinding a stoichiometric quantity of LiOH·H₂O with each of the solid acids. X-ray powder diffraction data show …
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Lithium-ion Battery Devices as a Method of Doping Metal Halide Perovskites
… The first study in Chapter 4 considers Ruddlesden-Popper 2D/3D perovskites from an energy storage point of view. In doing so, the macroscopic lithiation processes that occur when a perovskite electrode is subjected to galvanostatic cycling are discussed. It is shown that a mixed 2D/3D …
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Influence of Electronic Structure and Lattice Dynamics on Oxygen Ion Transport in Solid-State Ionic Conductors
… vacancies and interstitials in perovskite and RuddlesdenPopper oxides. We find that defect formation energy rises with defect formation entropy, which is linked to electronic energy states interacting with phonons. In perovskite oxides, lower vacancy formation entropy is correlated with …
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Topochemical Manipulation of Layered Perovskites
… intercalation of halogens into a series of Ruddlesden-Popper (R-P) ruthenate oxides with the formula Ae</p> n+1RunO3n+1 (Ae = Ca, Sr; n = 1, 2, 3) using several sources of fluorine, chlorine, and bromine. A new method was developed to intercalate chlorine into layered systems; this new …
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Fundamental studies of perovskite related oxide thin films for oxygen electrocatalysis at intermediate temperatures
… In this thesis, two promising strategies, 1) Ruddlesden-Popper (RP) oxides and 2) surface decoration on the MIEC oxides are proposed to design highly active oxide materials and improve the fundamental understanding of the oxygen electrocatalysis at intermediate temperature. The oxygen surface …
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XANES und MEXAFS an magnetischen Übergangsmetalloxiden : Entwicklung eines digitalen Lock-In-XMCD-Experiments mit Phasenschieber
… eine Erhöhung der Curie-Temperatur, was bei Ruddlesden-Popper Phasen zum ersten Mal beobachtet wurde. Das Ru-Untergitter und das Mn-Gitter sind zueinander antiparallel gekoppelt. Durch Bestimmung der Valenzen von Mn und Ru wird ein dem Superaustausch ähnliches Kopplungsmodell entworfen, womit …
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Controlled Attachment of Nanoparticles to Layered Oxides
… propoxyl-HLaNb<sub>2</sub>O<sub>7</sub> (pHLN), Ruddlesden-Popper phase perovskite H<sub>2</sub>SrTa<sub>2</sub>O<sub>7</sub> (HSTO) and Aurivillius phase perovskite H<sub>2</sub>W<sub>2</sub>O<sub>7</sub> (HWO) were synthesized and functionalized with gold NPs by in-situ methods. Gold NPs were …
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Structural studies of layered transition metal oxides
… their structures based on the n = 2 Ruddlesden-Popper layered perovskites. Their<br/>structures were determined through Rietveld refinement against X-ray and neutron powder<br/>diffraction, supported by vibrating sample magnetometry and thermal analysis.<br/><br/>The structure of the …
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Towards first-principles prediction of electrocatalytic activity of ABO₃ perovskites
… and 4) demonstrating the high efficiency of Ruddlesden-Popper (RP) perovskties. To this end, we have derived a general formalism for incorporating pH- and U-dependent ion exchange at the catalyst surface-solvent interface, and used this approach to determine the surface structure/composition …
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Spin dynamics of bulk and quasi-two-dimensional metal halide based perovskite semiconductors
… and induce spin depolarisation in the quasi-2d Ruddlesden-Popper hybrid metal-halide perovskite Butylammonium Formamidinium Lead Iodide, BA<sub>2</sub>FAPBI<sub>7</sub>. Experiments were carried out jointly between Dr Ravichandran Shivanna and me. For carrier densities above ~10<sup>15</sup> …
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Controlling properties of functional oxides by tuning oxygen defect chemistry
… strain on oxygen defect formation energy in Ruddlesden-Popper (RP) phase oxide Nd2NiO4+6 (NNO). We found that tensile strain along the c-axis of NNO lattice effectively reduced the formation enthalpy of oxygen interstitials, which can provide a new route for designing the defect chemistry of …