Kooperativer Bibliotheksverbund

Berlin Brandenburg

and
and

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
Language
Year
  • 1
    Language: English
    In: Applied Physics Letters, 28 July 2014, Vol.105(4)
    Description: We report on the fabrication of high quality (1 1 1)-oriented ferrimagnetic normal spinel CoCr{sub 2}O{sub 4} epitaxial thin films on single crystal Al{sub 2}O{sub 3} substrates. The structural, electronic, and magnetic properties were characterized by in-situ reflection high energy electron diffraction, atomic force microscopy, X-ray diffraction, X-ray photoemission spectroscopy, dc magnetization measurement, and element resolved resonant X-ray magnetic scattering. The comprehensive characterization reveals that no disorder in the cation distribution or multivalency issue is present in the samples. As a result, Kagomé and triangular layers are naturally formed via this specific growth approach. These findings offer a pathway to fabricate two dimensional Kagomé heterostructures with exotic quantum many-body phenomena by means of geometrical design.
    Keywords: Condensed Matter Physics, Superconductivity And Superfluidity ; Aluminium Oxides ; Atomic Force Microscopy ; Chromium Compounds ; Cobalt Compounds ; Crystal Structure ; Electrical Properties ; Electron Diffraction ; Epitaxy ; Layers ; Magnetic Properties ; Magnetization ; Monocrystals ; Oxygen Compounds ; Photoemission ; Reflection ; Spectroscopy ; Substrates ; Two-Dimensional Calculations ; X Radiation ; X-Ray Diffraction ; Engineering ; Physics
    ISSN: 0003-6951
    E-ISSN: 1077-3118
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Language: English
    In: Applied Physics Letters, 16 May 2016, Vol.108(20)
    Description: Graphene's linear dispersion relation and the attendant implications for bipolar electronics applications have motivated a range of experimental efforts aimed at producing p-n junctions in graphene. Here we report electrical transport measurements of graphene p-n junctions formed via simple modifications to a PbZr{sub 0.2}Ti{sub 0.8}O{sub 3} substrate, combined with a self-assembled layer of ambient environmental dopants. We show that the substrate configuration controls the local doping region, and that the p-n junction behavior can be controlled with a single gate. Finally, we show that the ferroelectric substrate induces a hysteresis in the environmental doping which can be utilized to activate and deactivate the doping, yielding an “on-demand” p-n junction in graphene controlled by a single, universal backgate.
    Keywords: Classical And Quantum Mechanics, General Physics ; Configuration ; Configuration Control ; Dispersion Relations ; Dispersions ; Doped Materials ; Ferroelectric Materials ; Graphene ; Hysteresis ; Layers ; P-N Junctions ; Substrates ; Engineering ; Physics
    ISSN: 0003-6951
    E-ISSN: 1077-3118
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Language: English
    In: Applied Physics Letters, 15 September 2014, Vol.105(11)
    Description: Dark state physics has led to a variety of remarkable phenomena in atomic physics, quantum optics, and information theory. Here, we investigate interacting dark resonance type physics in multi-layered plasmonic meta-molecules. We theoretically demonstrate that these plasmonic meta-molecules exhibit sub-natural spectral response, analogous to conventional atomic four-level configuration, by manipulating the evanescent coupling between the bright and dark elements (plasmonic atoms). Using cascaded coupling, we show nearly 4-fold reduction in linewidth of the hybridized resonance compared to a resonantly excited single bright plasmonic atom with same absorbance. In addition, we engineered the geometry of the meta-molecules to realize efficient intramolecular excitation transfer with nearly 80%, on resonant excitation, of the total absorption being localized at the second dark plasmonic atom. An analytical description of the spectral response of the structure is presented with full electrodynamics simulations to corroborate our results. Such multilayered meta-molecules can bring a new dimension to higher quality factor plasmonic resonance, efficient excitation transfer, wavelength demultiplexing, and enhanced non-linearity at nanoscale.
    Keywords: Condensed Matter Physics, Superconductivity And Superfluidity ; Absorption ; Atoms ; Coupling ; Electrodynamics ; Excitation ; Layers ; Molecules ; Nanostructures ; Quality Factor ; Reduction ; Resonance ; Simulation ; Spectral Response ; Wavelengths ; Engineering ; Physics
    ISSN: 0003-6951
    E-ISSN: 1077-3118
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Language: English
    In: Journal of Applied Physics, 28 February 2015, Vol.117(8)
    Description: Monte Carlo simulations show that roughness in uncompensated antiferromagnets decreases not just the surface magnetization but also the net magnetization and particularly strongly affects the temperature dependence. In films with step-type roughness, each step creates a new compensation front that decreases the global net magnetization. The saturation magnetization decreases non-monotonically with increasing roughness and does not scale with the surface area. Roughness in the form of surface vacancies changes the temperature-dependence of the magnetization; when only one surface has vacancies, the saturation magnetization will decrease linearly with surface occupancy, whereas when both surfaces have vacancies, the magnetization is negative and exhibits a compensation point at finite temperature, which can be tuned by controlling the occupancy. Roughness also affects the spin-texture of the surfaces due to long-range dipolar interactions and generates non-collinear spin configurations that could be used in devices to produce locally modified exchange bias. These results explain the strongly reduced magnetization found in magnetometry experiments and furthers our understanding of the temperature-dependence of exchange bias.
    Keywords: Condensed Matter Physics, Superconductivity And Superfluidity ; Computerized Simulation ; Films ; Magnetization ; Monte Carlo Method ; Roughness ; Spin ; Surface Area ; Surfaces ; Temperature Dependence ; Texture ; Vacancies ; Engineering ; Physics
    ISSN: 0021-8979
    E-ISSN: 1089-7550
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Language: English
    In: Phys. Rev. B, 01 January 2010, Vol.81(2010)
    Description: We derive the spin Hamiltonian for the quantum spin liquid Na{sub 4}Ir{sub 3}O{sub 8}, and then estimate the direct and superexchange contributions between near neighbor iridium ions using a tight-binding parametrization of the electronic structure. We find a magnitude of the exchange interaction comparable to experiment for a reasonable value of the on-site Coulomb repulsion. For one of the two tight-binding parametrizations we have studied, the direct exchange term, which is isotropic, dominates the total exchange. This provides support for those theories proposed to describe this quantum spin liquid that assume an isotropic Heisenberg model.
    Keywords: Physics Of Elementary Particles And Fields ; Atomic And Molecular Physics ; Coulomb Field ; Electronic Structure ; Exchange Interactions ; Hamiltonians ; Heisenberg Model ; Iridium Ions ; Spin ; Physics
    ISSN: 1098-0121
    E-ISSN: 1550-235X
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Language: English
    In: J. Am. Chem. Soc, 01 January 2010, Vol.132(2010)
    Description: The Lewis acidic ionic liquid EMIMBr-AlCl{sub 3} (EMIM = 1-ethyl-3-methylimidazolium) allows a novel synthetic route to the semiconducting layered metal chalcogenides halide [Bi{sub 2}Te{sub 2}Br](AlCl{sub 4}) and its Sb analogue. [Bi{sub 2}Te{sub 2}Br](AlCl{sub 4}) is a direct band gap, strongly anisotropic semiconductor and consists of cationic infinite layers of [Bi{sub 2}Te{sub 2}Br]{sup +} and [AlCl{sub 4}]{sup -} anions inserted between the layers.
    Keywords: Inorganic, Organic, Physical And Analytical Chemistry ; Anions ; Chalcogenides ; Halides ; Synthesis ; Chemistry
    ISSN: 0002-7863
    E-ISSN: 1520-5126
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Language: English
    In: Applied Physics Letters, 22 September 2014, Vol.105(12)
    Description: The role of chemistry, film thickness, and oxygen pressure in influencing the electrical and thermal transport properties of LaAlO{sub 3}/SrTiO{sub 3} heterointerfaces is explored. Unit-cell precise growth was accomplished for films between 3 and 160 unit cells thick using reflection high-energy electron diffraction-assisted pulsed-laser deposition. Subsequent temperature-dependent studies of electrical resistivity reveal three important observations: (1) by tuning the laser fluence, we can systematically tune the interfacial conductance in a step-wise manner in this system, (2) all films exhibit a critical thickness of 3–4 unit cells for the onset of conduction, and (3) the nature of the conductance is highly influenced by the stoichiometry of the LaAlO{sub 3} film with La-deficient samples showing dramatic changes with thickness, while stoichiometric and La-excess films show little dependence. Time-domain thermoreflectance studies show a diminished interfacial thermal conductance for the La-deficient films when compared to La-excess and stoichiometric films, suggesting that the interfacial conductance is more influenced by extrinsic factors such as oxygen deficiency.
    Keywords: Condensed Matter Physics, Superconductivity And Superfluidity ; Aluminates ; Crystal Growth ; Electric Conductivity ; Electron Diffraction ; Energy Beam Deposition ; Films ; Lanthanum Compounds ; Laser Radiation ; Pulsed Irradiation ; Reflection ; Stoichiometry ; Strontium Titanates ; Temperature Dependence ; Thermal Conductivity ; Thickness ; Engineering ; Physics
    ISSN: 0003-6951
    E-ISSN: 1077-3118
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Language: English
    In: Applied Physics Letters, 24 February 2014, Vol.104(8)
    Description: Multiferroic BiFeO{sub 3} (BFO)/La{sub 0.7}Sr{sub 0.3}MnO{sub 3} heterostructured thin films were grown by pulsed laser deposition on polished spark plasma sintered LaAlO{sub 3} (LAO) polycrystalline substrates. Both polycrystalline LAO substrates and BFO films were locally characterized using electron backscattering diffraction, which confirmed the high-quality local epitaxial growth on each substrate grain. Piezoforce microscopy was used to image and switch the piezo-domains, and the results are consistent with the relative orientation of the ferroelectric variants with the surface normal. This high-throughput synthesis process opens the routes towards wide survey of electronic properties as a function of crystalline orientation in complex oxide thin film synthesis.
    Keywords: Condensed Matter Physics, Superconductivity And Superfluidity ; 70 Plasma Physics And Fusion Technology ; Aluminates ; Electron Diffraction ; Energy Beam Deposition ; Epitaxy ; Ferrates ; Ferroelectric Materials ; Lanthanum Oxides ; Laser Radiation ; Microscopy ; Plasma ; Polycrystals ; Pulsed Irradiation ; Switches ; Thin Films ; Engineering ; Physics
    ISSN: 0003-6951
    E-ISSN: 1077-3118
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Language: English
    In: Phys. Rev. Lett, 08 January 2010, Vol.104(Jan. 8, 2010)
    Description: The spin-liquid candidate {kappa}-(BEDT-TTF){sub 2}Cu{sub 2}(CN){sub 3} has been studied by measuring the uniaxial expansion coefficients {alpha}{sub i}, the specific heat, and magnetic susceptibility. Special emphasis was placed on the mysterious anomaly around 6K - a potential spin-liquid instability. Distinct and strongly anisotropic lattice effects have been observed at 6K, clearly identifying this feature as a second-order phase transition. Owing to the large anomalies in {alpha}{sub i}, the application of Grueneisen scaling has enabled us to determine the corresponding specific heat contribution and the entropy release. Comparison of the latter with available spin models suggests that spin degrees of freedom alone cannot account for the phase transition. Scenarios, involving charge degrees of freedom, are discussed.
    Keywords: Classical And Quantum Mechanics, General Physics ; Degrees Of Freedom ; Entropy ; Instability ; Magnetic Susceptibility ; Specific Heat ; Spin ; Physics
    ISSN: 0031-9007
    E-ISSN: 1079-7114
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Language: English
    In: Phys. Rev. Lett, 05 March 2010, Vol.104(Mar. 5, 2010)
    Description: With the help of first-principles-based computational techniques, we demonstrate that Goldstone-like states can be artificially induced in a layered-perovskite ferroelectric compound with frustrated polarization, resulting in the emergence of a variety of interesting physical properties that include large, tunable dielectric constants and an ability to easily form vortex polar states in a nanodot geometry. In a similar fashion to the well-known perovskite materials with morphotropic phase boundaries (MPBs), these states manifest themselves as polarization rotations with almost no energy penalty, suggesting that the existence of an MPB is actually yet another manifestation of the Goldstone theorem in solids.
    Keywords: Classical And Quantum Mechanics, General Physics ; Geometry ; Permittivity ; Perovskite ; Physical Properties ; Polarization ; Physics
    ISSN: 0031-9007
    E-ISSN: 1079-7114
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. Further information can be found on the KOBV privacy pages