Materials Literature
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We employ a dual-gated geometry to control the band gap $\ensuremath{\Delta}$ in bilayer graphene and study the temperature dependence of the resistance at the charge neutrality point, ${R}_{\text{NP}}(T)$, from 220 to 1.5 K. Above 5 K, ${R}_{\text{NP}}(T)$ is dominated by two thermally activated processes in differen…
We report on the crystal structure of the quantum magnet (CuCl)LaNb2O7 that was controversially described with respect to its structural organization and magnetic behavior. Using high-resolution synchrotron powder x-ray diffraction, electron diffraction, transmission electron microscopy, and band structure calculation…
XPS, TEM, and reaction studies were used to examine the catalytic behavior of gold species deposited on lanthana toward the cross-coupling of phenylacetylene and iodobenzene. Atomically dispersed Au(I) and Au(III) were catalytically inert, whereas metallic Au(0) nanoparticles were both active and very selective. Thus…
Niobium-based Superconducting Radio Frequency (SRF) cavity performance is sensitive to localized defects that give rise to quenches at high accelerating gradients. In order to identify these material defects on bulk Nb surfaces at their operating frequency and temperature, it is important to develop a new kind of wide…
Electrical resistivity, specific-heat, and NMR measurements classify noncentrosymmetric ${\text{Mo}}_{3}{\text{Al}}_{2}\text{C}$ ($\ensuremath{\beta}\text{-Mn}$ type, space group $P{4}_{1}32$) as a strong-coupled superconductor with ${T}_{c}=9\text{ }\text{K}$ deviating notably from BCS-type behavior. The absence of a…
We study the optical spectra and electromagnetic field enhancements around cylindrical and triangular Ag nanowire dimers, allowing for a spatially nonlocal dielectric function that partially accounts for quantum mechanical effects. For the triangular structures, we pay particular attention to how these properties depe…
We report on the exchange biasing of self-assembled ferromagnetic GeMn nanocolumns by GeMn-oxide caps. The x-ray absorption spectroscopy analysis of this surface oxide shows a multiplet fine structure that is typical of the Mn2+ valence state in MnO. A magnetization hysteresis shift |HE|~100 Oe and a coercivity enhanc…
ZnO nanoparticles (NP) of size less than around 20 nm inside a chamber exhibits complete reduction in their visible photoluminescence (PL) intensity when partial pressure of oxygen in the surrounding gaseous environment is decreased by evacuation. However the visible PL from ZnO nanoparticles are insensitive to the ga…
This paper has been withdrawn by the author.
We show that silicon nitride can provide uniform coverage of graphene in field-effect transistors while preserving the channel mobility. This insulator allowed us to study the maximum channel resistance at the Dirac (neutrality) point as a function of the strength of a perpendicular electric field in top-gated devices…
Abstract NaCaPO 4 :Ce 3+ ,Tb 3+ phosphors were prepared by a solid‐state reaction. Their luminescence properties reveal that an efficient energy transfer from the Ce 3+ to Tb 3+ ions occurs, and its mechanism is a resonant type by means of a dipole–quadrupole reaction. The critical distance of the energy transfer has…
Particular strain geometry in graphene could lead to a uniform pseudomagnetic field of order 10T and might open up interesting applications in graphene nanoelectronics. Through quantum transport calculations of realistic strained graphene flakes of sizes of 100 nm, we examine possible means of exploiting this effect f…
Treatment of 1-amino-1,2,3-triazole with sodium dichloroisocyanurate led to isolation of 1,1'-azobis-1,2,3-triazole, which was well characterized. Its structure was determined by X-ray crystallographic analysis, and its thermal stability and photochromic properties were investigated.
The local atomic structure of graphene oxide (GO) and reduced annealed graphene oxide (raGO) is determined via ultra-high-resolution transmission electron microscopy. We find that the proposed and desired return to graphene from GO is not possible through the synthetic route employed. The detailed structure of GO, pre…
A Lattice Monte Carlo (LMC) simulation technique has been developed to describe the synthesis of a single semiconductor nanocrystal inside the droplets of a microemulsion. The LMC simulation can track the diffusion of a precursor, its irreversible reaction with a second precursor to form nuclei, and the diffusion and…
Decreasing the forming time in gas blow forming using fine grained Mg alloy AZ31B thin sheet with a thickness of 0·6 mm was studied in this work. Tensile tests and gas blow forming using stepwise pressurisation profiles were performed to explore the deformation behaviour of a fine grained AZ31B Mg alloy sheet. The all…
Abstract Computer simulations reveal the unique conformation of or erythro diisotactic polynorbornene, a polymer with numerous important applications in microelectronics. While previous simulations suggested that this polymer adopts a helix‐kink morphology, the results presented herein indicate that the reversal of th…
New proton-ionizable p-tert-butylcalix-4-arene ligands with three N-(X)sulfonyl oxyacetamide groups and one methoxy group on the lower rim capable of forming electroneutral complexes with trivalent lanthanide ions are synthesized. Variation of the electron-withdrawing ability of X (Me, Ph, C6H4-4-NO2, CF3) is used to…
Abstract A series of optically inactive polythiophene derivatives bearing the azobenzene moiety are synthesized in an isotropic toluene solution. The polymers are then dissolved in a cholesteric liquid crystal (Ch*LC) medium within the liquid crystal (LC) temperature range. The dissolution process in Ch*LC produces in…
Abstract In this paper, we report on the transport properties of nanostructured boron doped diamond thin films. The nanostructures made from polycrystalline boron doped diamond show clear evidence of superconductivity with critical temperatures in the Kelvin range and critical field in the Tesla range. Such robust sup…