Materials Literature
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A magnetoresistance study of carbon nanotubes demonstrates that, for small diameters, the location of the chemical potential and the orientation of the magnetic field are parameters that enable tuning from positive to negative magnetoresistance, a phenomenon not related with weak localization. For larger diameters (>…
The complex dielectric functions of wurtzite ZnS thin films grown on (0001) Al2O3 have been determined by using spectroscopic ellipsometry over the spectral range of 1.33–4.7 eV. Below the band gap, the refractive index n is found to follow the first-order Sellmeir dispersion relationship n2(λ)=1+2.22λ2/(λ2−0.0382). S…
Experimental measurements of Raman spectra for hcp iron at high pressure show two modes over a considerable pressure range in contrast to the prediction of one doubly degenerate mode for the hcp lattice. We use density functional theory to investigate the influence of magnetic order on the Raman active modes of hcp ir…
We report the discovery of a new class of molecular phases of solid nitrogen at high pressures and temperatures by Raman and infrared spectroscopy and powder x-ray diffraction. Unlike the molecular phases consisting of disk- and sphere-like molecular disorder ($δ$-, $ε$- and $ζ$-N$_2$) and reportedly stable over a wid…
The spin-polarized scanning tunnelling microscope (STM) can in principle resolve not only the electronic, but also the magnetic surface structure. We model recent STM measurements achieving magnetic resolution on the atomic scale by a first-principles method. It is shown that the signature of a specific magnetic or no…
Spin relaxation time of conduction electrons through the Elliot-Yafet, D'yakonov-Perel and Bir-Aronov-Pikus mechanisms is calculated theoretically for bulk GaAs, GaSb, InAs and InSb of both $n$- and $p$-type. Relative importance of each spin relaxation mechanism is compared and the diagrams showing the dominant mechan…
We have performed the most realistic simulation to date of the operation of a scanning tunneling microscope. Probe-sample distances from beyond tunneling to actual surface contact are covered. We simultaneously calculate forces, atomic displacements, and tunneling currents, allowing quantitative comparison with experi…
In this paper the fabrication process for a screen-printable magnetostrictive thick-film material based upon the giant magnetostrictive material, Terfenol-D, is reported. Factors affecting the magnetostriction of the printed thick film have been identified, and suitable parameters selected to yield a functional thick…
Two 2D coordination polymers [M(NCS)2(pzdo)2] (M = Mn, Co; pzdo = pyrazine dioxide) bridged by pzdo ligand are synthesized, which are found to exhibit antiferromagnetic ordering below 8.4 and 11.2 K, respectively.
Hexagonal boron nitride films on Si(100) substrates are formed from the system N2/B(OCH3)3 (TMOB) by microwave plasma enhanced chemical vapour deposition (PECVD). The parameters substrate temperature, deposition time and composition of the process gas mixture were varied. The stability of the deposited layers mainly d…
Acetylene-substituted tetra[6,7]quinoxalinoporphyrazines, obtained in two steps from dialkynyl-1,2-diones and 1,2-diamino-4,5-dicyanobenzene, show intense absorptions in the near infrared and have photooxidising properties that make them promising candidates as agents active in photodynamic therapy.
Floating drops of magnetic fluid can be brought into rotation by applying a rotating magnetic field. We report theoretical and experimental results on the transition from a spheroid equilibrium shape to non-axissymmetrical three-axes ellipsoids at certain values of the external field strength. The transitions are cont…
We have assigned the chirality of the internal tubes of double walled carbon nanotubes grown by catalytic chemical vapor deposition using the high sensitivity of the radial breathing mode (RB) in inelastic light scattering experiments. The deduced chirality corresponds to several semiconducting and only two metallic i…
>From magnetic storage to catalysts, the useful properties of many materials can be traced back to the presence of metallic elements. But introducing metals into polymers has been a synthetic challenge. In his Perspective, Manners describes recent progress toward polymers in which metallic elements act as structural c…
We have used the pH-induced self-assembly of a peptide-amphiphile to make a nanostructured fibrous scaffold reminiscent of extracellular matrix. The design of this peptide-amphiphile allows the nanofibers to be reversibly cross-linked to enhance or decrease their structural integrity. After cross-linking, the fibers a…
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Abstract The infrared and Raman spectra of silver saccharinate Ag(C 7 H 4 NO 3 S), were recorded and are briefly discussed on the basis of its structural characteristics and by comparison with the spectra of some related species. Copyright © 2001 John Wiley & Sons, Ltd.
The mechanism of chemiluminescence (CL) during thermal oxidation of polypropylene (PP) was probed by doping PP with an energy acceptor (9,10-dibromoanthracene [DBA]) and a chemiluminescence (CL) activator (9,10-diphenylanthracene [DPA]). Doping PP with DBA had little effect on the shape of the CL intensity ( I CL )−ti…
We show that the transition in AMnO 3 from the orthorhombic perovskite phase to the hexagonal phase is promoted by inducing site disorder on the A-site. The gap between the orthorhombic and the hexagonal phase is widened for site disordered, mixed yttrium−gadolinium manganite samples. At the cost of the orthorhombic p…
Binuclear Co(II)Co(II), Co(II)Co(III) and Co(III)Co(III) complexes are reported of dianionic ligands, L2−, derived from the condensation of two mol of salicylaldehyde, or substituted salicylaldehydes, and one mol of methanediamine or phenyl substituted methanediamines. Direct evidence for the binuclear nature of the c…