2,089 publications from this institution
Layered materials composed of a single element form a new family of 2D materials. Graphene is a well-known 2D material of this family with potential applications. 2D materials of other elements which are located around carbon in the periodic table have recently come to the fore. Borophene in group-III, silicene, germanene and stanene in group-IV are synthetic 2D materials, showing stability on suitable substrates. Phosphorene, arsenene, antimonene and bismuthene in group-V are obtained from exfoliation of their layered bulk allotropes. Silicene, phosphorene and antimonene are interesting in terms of stability and properties leading to possible applications. Chemically functionalized phosphorene shows ambient stability and good photocatalytic activity. More information can be found in the Minireview by C. N. R. Rao et al. on page 1062 in Issue 9, 2019 (DOI: 10.1002/cnma.201900176).
No abstract is provided for this article.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Superconducting Tl 1−δ CaBa 2 Cu 2 O 7 can be prepared without impurity from the corresponding two Tl-O layer cuprate only when some Tl deficiency is incorporated. The Tl 1−δ CaBa 2 Cu 2 O 7 and Tl 1−δ Y 1−x Ca x Ba 2 Cu 2 O 7 series show maximum T c at an optimal hole concentration. The T c maximum occurs at a Cu—O distance of ca. 1.924 A.
No abstract is provided for this article.
A. W. Czanderna, C. N. R. Rao and J. M. Honig, Trans. Faraday Soc., 1958, 54, 1069 DOI: 10.1039/TF9585401069
The interaction of oxygen with Ni(100), (110) and (111) surfaces as well as with Ni clusters of varying sizes has been investigated by employing core-level spectroscopy. On single-crystal surfaces, the main oxygen species are O1− and O2− with characteristic O(1s) binding energies of 531 and 530 eV, the percentage of the former being ∼30. At relatively high oxygen exposures, Ni2+ and Ni3+ are found on these surfaces. On the surfaces of small clusters, O1− is the primary product (≥ 50%) and the proportion of the O2− species increases with the cluster size. The small clusters distinctly show that Ni2+ is formed first, followed by Ni3+ at higher exposures. A sequence of transformations occurring on Ni surfaces exposed to oxygen is suggested.
Giant magnetoresistance (GMR), which was until recently confined to magnetic layered and granular materials, as well as doped magnetic semiconductors, occurs in manganate perovskites of the general formula Ln1-xAxMnO3 (Ln = rare earth; A = divalent ion). These manganates are ferromagnetic at or above a certain value of x (or Mn4+ content) and become metallic at temperatures below the curie temperature, Tc. GMR is generally a maximum close to Tc or the insulator−metal (I−M) transition temperature, Tim. The Tc and %MR are markedly affected by the size of the A site cation, 〈rA〉, thereby affording a useful electronic phase diagram when Tc or Tim is plotted against 〈rA〉. We discuss GMR and related properties of manganates in polycrystalline, thin-film, and single-crystal forms and point out certain commonalities and correlations. We also examine some unusual features in the electron-transport properties of manganates, in particular charge-ordering effects. Charge ordering is crucially dependent on 〈rA〉 or the eg band width, and the charge-ordered insulating state transforms to a metallic ferromagnetic state on the application of a magnetic field.
No abstract is provided for this article.
Article MetricsDownloadsCitationsNo data available.01234JulAugSepOctNovDec220Total6 Months12 MonthsTotal number of downloads for the most recent 6 whole calendar months.
No abstract is provided for this article.
Monte Carlo simulation studies predict a glass transition in methanol around 180K (experimental T g , 160K). Methanol exists mainly in the form of linear hydrogen bonded polymers with an average of 10 molecules per polymeric unit in the glass at 180K compared to 6 molecules per unit in the liquid at 298K. There is a considerably greater preponderence of the polymeric. species in the glass relative to the liquid. There is a small change in the distribution of the hydrogen bonded species at T g , but a significant breaking down of the polymeric species occurs above 220K. The average coordination number as well as the g min /g max ratios show a change around 220K instead of at T g . The simulated distribution of hydrogen bonded species is comparable to the results obtained from infra-red spectroscopy.
