Ultra-small cobalt particles embedded in titania by ion beam synthesis: Additional datasets including electron microscopy, neutron reflectometry, modelling outputs and particle size analysis.

This Data-in-brief article includes datasets of electron microscopy, polarised neutron reflectometry and magnetometry for ultra-small cobalt particles formed in titania thin films via ion beam synthesis. Raw data for polarised neutron reflectometry, magnetometry and the particle size distribution are included and made available on a public repository. Additional elemental maps from scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) are also presented.

Origin of Metallic Nature of NaN.

Among inorganic clathrates, the inner cavity space rarely affects the electronic structure of the framework. We report that the anti-ReO-type compound NaN has a metallic nature irrespective of the stoichiometric chemical composition of simple representative elements and that this unusual nature originates from the collapse of the bandgap owing to the presence of a crystallographic cavity. We synthesized NaN by the plasma-assisted nitridation of alkali metals, and diffuse reflectance measurements indicated a metallic nature.

Enhanced Magnetization of Cobalt Defect Clusters Embedded in TiO Films.

High magnetizations are desirable for spintronic devices that operate by manipulating electronic states using built-in magnetic fields. However, the magnetic moment in promising dilute magnetic oxide nanocomposites is very low, typically corresponding to only fractions of a Bohr magneton for each dopant atom. In this study, we report a large magnetization formed by ion implantation of Co into amorphous TiO films, producing an inhomogeneous magnetic moment, with certain regions producing over 2.

Proton conduction mechanisms in the phosphoric acid-water system (HPO-HPO·2HO): a H, P and O PFG-NMR and conductivity study.

Ionic charge carrier formation and mobility, including the underlying conduction mechanisms, are investigated for phosphoric acid at water contents relevant for the acid's application as electrolyte in fuel cells. The high conductivity contribution from structural diffusion involving intermolecular proton transfer (∼97%) in neat phosphoric acid (HPO) passes through a maximum at this composition. Hydrogen bond network frustration (imbalance of the number of proton donors and acceptors), which is closely related to the appearance of structural diffusion, decreases with both elimination and addition of water.

High-Tc superconductivity in ultrathin Bi2Sr2CaCu2O(8+x) down to half-unit-cell thickness by protection with graphene.

High-Tc superconductors confined to two dimension exhibit novel physical phenomena, such as superconductor-insulator transition. In the Bi2Sr2CaCu2O(8+x) (Bi2212) model system, despite extensive studies, the intrinsic superconducting properties at the thinness limit have been difficult to determine. Here, we report a method to fabricate high quality single-crystal Bi2212 films down to half-unit-cell thickness in the form of graphene/Bi2212 van der Waals heterostructure, in which sharp superconducting transitions are observed.

Collective modes and the periodicity of quantum Hall stripes.

We investigate the quantum Hall stripe phase at filling factor 9/2 at the microscopic level by probing the dispersion of its collective modes with the help of surface acoustic waves with wavelengths down to 60 nm. The dispersion is strongly anisotropic. It is highly dispersive and exhibits a roton minimum for wave vectors aligned along the easy transport direction.

Full simulations of the apertureless scanning near field optical microscopy signal: achievable resolution and contrast.

We simulate apertureless near-field optical imaging and obtain phase and amplitude scans of structured substrates for elastic scattering. The solution of the three-dimensional Maxwell equations does not involve approximations and we include large tips and substrates, strong interaction, interferometric detection and demodulation at higher harmonics. Such modeling represents a significant step towards quantitative simulations and offers the attractive possibility to study the individual influence of each relevant experimental parameter.

Circular-polarization-dependent study of the microwave photoconductivity in a two-dimensional electron system.

The polarization dependence of the low field microwave photoconductivity and absorption of a two-dimensional electron system has been investigated in a quasioptical setup in which linear and any circular polarization can be produced in situ. The microwave induced resistance oscillations and the zero resistance regions are notably immune to the sense of circular polarization. This observation is discrepant with a number of proposed theories.

Many-body partition function and thermal hartree-fock approximations.

The hierarchy equations for the quantum thermal density matrices of an assembly of interacting particles in an external potential are derived in a compact form. This approach can complement and finally replace the phenomenological treatment of the thermodynamic properties of quantum gasses, liquids, and solids. We also derive a temperature Hartree-Fock approximation for fermions based on the symmetry properties of the exact hierarchy and finally we discuss the present approximation in relation to that of Kaplan and Argyres [T.